docs: Remove the warning about partially staged files (#5310)

Since partially staged files are now officially supported, this isn't up to date anymore.

docs/precommit.md

@@ -30,8 +30,6 @@ and add this config to your `package.json`:
 }
 ```
 
-**Warning:** Currently there is a limitation where if you stage specific lines this approach will stage the whole file after formatting. See this [issue](https://github.com/okonet/lint-staged/issues/62) for more info.
-
 See https://github.com/okonet/lint-staged#configuration for more details about how you can configure lint-staged.
 
 ## Option 2. [pretty-quick](https://github.com/azz/pretty-quick)