docs: Update shell code fences for new website (#15522)

Fixes #15518

docs/developer-guide/contributing/pull-requests.md

@@ -30,7 +30,7 @@ Details about each step are found below.
 
 The first step to sending a pull request is to create a new branch in your ESLint fork. Give the branch a descriptive name that describes what it is you're fixing, such as:
 
-```sh
+```shell
 $ git checkout -b issue1234
 ```
 
@@ -42,7 +42,7 @@ You should do all of your development for the issue in this branch.
 
 Make the changes to the code and tests, following the [code conventions](../code-conventions.md) as you go. Once you have finished, commit the changes to your branch:
 
-```sh
+```shell
 $ git add -A
 $ git commit
 ```
@@ -91,7 +91,7 @@ The commit message format is important because these messages are used to create
 
 Before you send the pull request, be sure to rebase onto the upstream source. This ensures your code is running on the latest available code.
 
-```sh
+```shell
 git fetch upstream
 git rebase upstream/main
 ```
@@ -100,7 +100,7 @@ git rebase upstream/main
 
 After rebasing, be sure to run all of the tests once again to make sure nothing broke:
 
-```sh
+```shell
 npm test
 ```
 
@@ -123,13 +123,13 @@ With your code ready to go, this is a good time to double-check your submission
 
 Next, push your changes to your clone:
 
-```sh
+```shell
 git push origin issue1234
 ```
 
 If you are unable to push because some references are old, do a forced push instead:
 
-```sh
+```shell
 git push -f origin issue1234
 ```
 
@@ -149,21 +149,21 @@ Once your pull request is sent, it's time for the team to review it. As such, pl
 
 If your commit message is in the incorrect format, you'll be asked to update it. You can do so via:
 
-```sh
+```shell
 $ git commit --amend
 ```
 
 This will open up your editor so you can make changes. After that, you'll need to do a forced push to your branch:
 
-```sh
+```shell
 $ git push origin issue1234 -f
 ```
 
 ### Updating the Code
 
 If we ask you to make code changes, there's no need to close the pull request and create a new one. Just go back to the branch on your fork and make your changes. Then, when you're ready, you can add your changes into the branch:
 
-```sh
+```shell
 $ git add -A
 $ git commit
 $ git push origin issue1234
@@ -177,13 +177,13 @@ The commit messages in subsequent commits do not need to be in any specific form
 
 If your code is out-of-date, we might ask you to rebase. That means we want you to apply your changes on top of the latest upstream code. Make sure you have set up a [development environment](../development-environment.md) and then you can rebase using these commands:
 
-```sh
+```shell
 $ git fetch upstream
 $ git rebase upstream/main
 ```
 
 You might find that there are merge conflicts when you attempt to rebase. Please [resolve the conflicts](https://help.github.com/articles/resolving-merge-conflicts-after-a-git-rebase/) and then do a forced push to your branch:
 
-```sh
+```shell
 $ git push origin issue1234 -f
 ```

docs/developer-guide/development-environment.md

@@ -14,7 +14,7 @@ Go to <https://github.com/eslint/eslint> and click the "Fork" button. Follow the
 
 Once you've cloned the repository, run `npm install` to get all the necessary dependencies:
 
-```sh
+```shell
 $ cd eslint
 $ npm install
 ```
@@ -27,7 +27,7 @@ The *upstream source* is the main ESLint repository where active development hap
 
 To add the upstream source for ESLint, run the following in your repository:
 
-```sh
+```shell
 git remote add upstream git@github.com:eslint/eslint.git
 ```
 
@@ -49,7 +49,7 @@ Please see the [generator documentation](https://github.com/eslint/generator-esl
 
 Running the tests is the best way to ensure you have correctly set up your development environment. Make sure you're in the `eslint` directory and run:
 
-```sh
+```shell
 npm test
 ```
 

docs/rules/no-mixed-operators.md

@@ -20,7 +20,7 @@ var foo = a && b || c || d;
 
 will generate
 
-```sh
+```shell
 1:13  Unexpected mix of '&&' and '||'. (no-mixed-operators)
 1:18  Unexpected mix of '&&' and '||'. (no-mixed-operators)
 ```
@@ -31,7 +31,7 @@ var foo = a && b ? c : d;
 
 will generate
 
-```sh
+```shell
 1:13  Unexpected mix of '&&' and '?:'. (no-mixed-operators)
 1:18  Unexpected mix of '&&' and '?:'. (no-mixed-operators)
 ```

docs/user-guide/command-line-interface.md

@@ -234,7 +234,7 @@ This option has the same effect as `--fix` with one difference: the fixes are no
 
 Because the default formatter does not output the fixed code, you'll have to use another one (e.g. `json`) to get the fixes. Here's an example of this pattern:
 
-```sh
+```shell
 getSomeText | eslint --stdin --fix-dry-run --format=json
 ```
 
@@ -251,7 +251,7 @@ This option allows you to specify the type of fixes to apply when using either `
 
 You can specify one or more fix type on the command line. Here are some examples:
 
-```sh
+```shell
 eslint --fix --fix-type suggestion .
 eslint --fix --fix-type suggestion --fix-type problem .
 eslint --fix --fix-type suggestion,layout .

docs/user-guide/getting-started.md

@@ -12,7 +12,7 @@ Prerequisites: [Node.js](https://nodejs.org/en/) (`^12.22.0`, `^14.17.0`, or `>=
 
 You can install ESLint using npm or yarn:
 
-```sh
+```shell
 npm install eslint --save-dev
 
 # or
@@ -22,7 +22,7 @@ yarn add eslint --dev
 
 You should then set up a configuration file, and the easiest way to do that is:
 
-```sh
+```shell
 $ npm init @eslint/config
 
 # or
@@ -34,7 +34,7 @@ $ yarn create @eslint/config
 
 After that, you can run ESLint on any file or directory like this:
 
-```sh
+```shell
 $ npx eslint yourfile.js
 
 # or

docs/user-guide/migrating-from-jscs.md

@@ -15,23 +15,23 @@ Before beginning the process of migrating to ESLint, it's helpful to understand
 
 To install Polyjuice:
 
-```sh
+```shell
 $ npm install -g polyjuice
 ```
 
 Polyjuice works with JSON configuration files, so if you're using a JavaScript or YAML JSCS configuration file, you should first convert it into a JSON configuration file.
 
 To convert your configuration file, pass in the location of your `.jscs.json` file using the `--jscs` flag:
 
-```sh
+```shell
 $ polyjuice --jscs .jscsrc.json > .eslintrc.json
 ```
 
 This creates a `.eslintrc.json` with the equivalent rules from `.jscsrc.json`.
 
 If you have multiple `.jscsrc.json` files, you can pass them all and Polyjuice will combine them into one `.eslintrc.json` file:
 
-```sh
+```shell
 $ polyjuice --jscs .jscsrc.json ./foo/.jscsrc.json > .eslintrc.json
 ```
 
@@ -41,7 +41,7 @@ $ polyjuice --jscs .jscsrc.json ./foo/.jscsrc.json > .eslintrc.json
 
 If you don't want to convert your JSCS configuration directly into an ESLint configuration, then you can use ESLint's built-in wizard to get you started. Just run:
 
-```sh
+```shell
 $ npm init @eslint/config
 ```
 
@@ -74,7 +74,7 @@ As an example, suppose that you are using the `airbnb` preset, so your `.jscsrc`
 
 In order to get the same functionality in ESLint, you would first need to install the `eslint-config-airbnb` shareable config package:
 
-```sh
+```shell
 $ npm install eslint-config-airbnb-base --save-dev
 ```
 
@@ -110,27 +110,27 @@ Both JSCS and ESLint have command line arguments corresponding to many of their
 
 JSCS uses the `--fix` option to apply automatic fixes to code:
 
-```sh
+```shell
 $ jscs --fix file.js
 ```
 
 ESLint has the same option:
 
-```sh
+```shell
 $ eslint --fix file.js
 ```
 
 ### `--auto-configure`
 
 The JSCS `--auto-configure` option created a configuration based on what it found in a given file:
 
-```sh
+```shell
 $ jscs --auto-configure file.js
 ```
 
 In ESLint, there's a similar option when you use `--init`. Just select "Inspect your JavaScript file(s)":
 
-```sh
+```shell
 $ eslint --init
 ? How would you like to configure ESLint? (Use arrow keys)
 > Answer questions about your style
@@ -142,14 +142,14 @@ $ eslint --init
 
 JSCS allows you to specify a configuration file to use on the command line using either `--config` or `-c`, such as:
 
-```sh
+```shell
 $ jscs --config myconfig.json file.js
 $ jscs -c myconfig.json file.js
 ```
 
 Both flags are also supported by ESLint:
 
-```sh
+```shell
 $ eslint --config myconfig.json file.js
 $ eslint -c myconfig.json file.js
 ```
@@ -158,12 +158,12 @@ $ eslint -c myconfig.json file.js
 
 In JSCS, you can pipe code in like this:
 
-```sh
+```shell
 $ cat file.js | jscs
 ```
 
 In ESLint, you can also pipe in code, but you need to use the `--stdin` flag:
 
-```sh
+```shell
 $ cat file.js | eslint --stdin
 ```