Describe the feature
You may wish to include the implementation of a particular function in the documentation.
For example, GitHub allows you to copy permalinks and do a range like package.json#L12-L13.

It is difficult to extract the beginning and end of a function by specifying the function name because the beginning and end of a function varies depending on the language, but it may be possible to extract only a specific line of the file, what do you think?
If it looks good, I would like to try to implement it.
Additional information