Merge pull request libgit2#4605 from cjhoward92/docs/cli-differences

docs: add documentation to state differences from the git cli

Author: pks-t

docs/differences-from-git.md

@@ -0,0 +1,20 @@
+# Differences from Git
+
+In some instances, the functionality of libgit2 deviates slightly from Git. This can be because of technical limitations when developing a library, licensing limitations when converting functionality from Git to libgit2, or various other reasons.
+
+Repository and Workdir Path Reporting
+-------------------------------------
+
+When asking Git for the absolute path of a repository via `git rev-parse --absolute-git-dir`, it will output the path to the ".git" folder without a trailing slash. In contrast to that, the call `git_repository_path(repo)` will return the path with a trailing slash:
+
+```
+git rev-parse --absolute-git-dir -> /home/user/projects/libgit2/.git
+git_repository_path(repo) -> /home/user/projects/libgit2/.git/
+```
+
+The same difference exists when listing worktrees:
+
+```
+git worktree list -> /home/user/projects/libgit2
+git_repository_workdir(repo) -> /home/user/projects/libgit2/
+```