Re: [PATCH 4/4] documentation: retire unfinished documentation

> When looking for documentation for a specific function, you may be tempted
> to run
>
>   git -C Documentation grep index_name_pos
>
> only to find the file technical/api-in-core-index.txt, which doesn't
> help for understanding the given function. It would be better to not find
> these functions in the documentation, such that people directly dive into
> the code instead.
>
> In the previous patches we have documented
> * index_name_pos()
> * remove_index_entry_at()
> * add_[file_]to_index()
> in cache.h
>
> We already have documentation for:
> * add_index_entry()
> * read_index()
>
> Which leaves us with a TODO for:
> * cache -> the_index macros
> * refresh_index()
> * discard_index()
> * ie_match_stat() and ie_modified(); how they are different and when to
>   use which.
> * write_index() that was renamed to write_locked_index
> * cache_tree_invalidate_path()
> * cache_tree_update()