Add documentation explaining lack of support for skipHash

libgit2 does not support skipHash which causes the prompt to be
incorrect for repos that have it toggled.

Add the documentation for this gap.

fixes #2387

README.md

@@ -1511,6 +1511,7 @@ Powerlevel10k are released. This may change in the future but not soon.
 - [Horrific mess when resizing terminal window](#horrific-mess-when-resizing-terminal-window)
 - [Icons cut off in Konsole](#icons-cut-off-in-konsole)
 - [Arch Linux logo has a dot in the bottom right corner](#arch-linux-logo-has-a-dot-in-the-bottom-right-corner)
+- [Git status looks incorrect](#git-status-looks-incorrect)
 
 ### Question mark in prompt
 
@@ -2020,3 +2021,15 @@ Some fonts have this incorrect dotted icon in bold typeface. There are two ways
 ```zsh
 typeset -g POWERLEVEL9K_OS_ICON_CONTENT_EXPANSION='${P9K_CONTENT}'  # not bold
 ```
+
+### Git status looks incorrect
+
+Powerlevel10k uses [gitstatus](https://github.com/romkatv/gitstatus) to provide a much faster response to traditional `git status`.
+The project relies on the [libgit2](https://github.com/libgit2/libgit2) library however which has some gaps in it's implementation.
+
+#### skipHash not supported
+
+If your `.git/config` has `skipHash` enabled, then you will likely see an incorrect status prompt as this is not supported
+by libgit2 at the moment. [issue](https://github.com/libgit2/libgit2/issues/6531)
+
+Note: `skipHash` can be set by implicitly by other configuration toggles such as `feature.manyFiles`