docs: Update CLI docs to prefer local install

[nzakas]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "X" next to an item)

[x] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofix to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

What changes did you make? (Give an overview)

Updated the CLI docs to use local install install of global. We don't recommend global install and so this was confusing for new users.

Also updated some of the code fences to "bash" from "sh" for better compatibility with the new syntax highlighter in the new website.

Fixes #15498

Is there anything you'd like reviewers to focus on?

Did I catch all of the examples?

[mdjermanovic]

Did I catch all of the examples?

All examples in code blocks are correctly fixed to npx eslint. I'm just not sure if the inline examples are intentionally left without npx:

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

  Line 27 in 03ac8cf

  The command line utility has several options. You can view the options by running `eslint -h`.

  (eslint -h)

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

  Line 148 in 03ac8cf

  For example, `eslint lib/* --ext .js` will match all files within the `lib/` directory, regardless of extension.

  (eslint lib/* --ext .js)

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

  Line 479 in 03ac8cf

  Add this flag to an ESLint command line invocation in order to get extra debug information as the command is run (e.g. `eslint --debug test.js` and `eslint test.js --debug` are equivalent)

  (eslint --debug test.js and eslint test.js --debug)

[nzakas]

Thanks, I’ll update the inline examples too for consistency.

[aladdin-add]

LGTM! 👍

[snitin315]

LGTM

[mdjermanovic]

LGTM, thanks!