Add releasing info to README

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

Author: PVince81

README.md

@@ -36,3 +36,16 @@ showError('This is an error shown without a timeout', { timeout: -1 })
 ```
 
 A full list of available options can be found in the [documentation](https://nextcloud.github.io/nextcloud-dialogs/).
+
+## Releasing a new version
+
+- Checkout latest master (pull);
+- Edit CHANGELOG.md and add new entries there for the new version, then create a commit;
+- Run `npm version patch` (`npm version minor` if minor). This will return a new version name, make sure it matches what was added in the CHANGELOG.md;
+- Push the tag and the master branch `git push origin master [printed-version-name]`;
+- Make the tag a release on github and add the changelog (https://github.com/nextcloud/nextcloud-dialogs/releases);
+- Click edit on a previous release and copy the body of the changelog;
+- Go back, click on your release and paste the copied text;
+- Edit all the version numbers;
+- Click on preview and click on view full changelog, this will show you all the prs that have been; added since the previous version;
+- Copy them in the changelog with the same format as previous ones;