FANDOM has disabled User Scripts from running on MediaWiki and User namespace pages that end with a '.JS' file extension. This severely reduces the effectiveness of this script. It still works on CSS pages, as well as JS pages that are not MediaWiki:Common.js or User:Name/wikia.js and so on but that's it.
By default, pressing the tab key changes focus from the textarea. This scripts makes the tab key produce a tab character instead, which might be necessary for some coders who prefer indenting by tabs.
The script runs only on pages ending with .js or .css.
In order to use this, put it in your w:Special:MyPage/global.js or wiki's Common.js. A helpful guide can be found here.
Follow the following instructions: