doc: avoid using the gender of other people

Using gendered pronouns for an anonymous person applies a gender where
none is known and further excludes readers who do not use gendered
pronouns. Avoid such examples in the documentation by using "they" or
passive voice to avoid the need for a pronoun.

Inspired-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/SubmittingPatches

@@ -370,9 +370,8 @@ If you like, you can put extra tags at the end:
 . `Acked-by:` says that the person who is more familiar with the area
   the patch attempts to modify liked the patch.
 . `Reviewed-by:`, unlike the other tags, can only be offered by the
-  reviewer and means that she is completely satisfied that the patch
-  is ready for application.  It is usually offered only after a
-  detailed review.
+  reviewers themselves when they are completely satisfied with the
+  patch after a detailed analysis.
 . `Tested-by:` is used to indicate that the person applied the patch
   and found it to have the desired effect.
 

Documentation/git-push.txt

@@ -244,8 +244,8 @@ Imagine that you have to rebase what you have already published.
 You will have to bypass the "must fast-forward" rule in order to
 replace the history you originally published with the rebased history.
 If somebody else built on top of your original history while you are
-rebasing, the tip of the branch at the remote may advance with her
-commit, and blindly pushing with `--force` will lose her work.
+rebasing, the tip of the branch at the remote may advance with their
+commit, and blindly pushing with `--force` will lose their work.
 +
 This option allows you to say that you expect the history you are
 updating is what you rebased and want to replace. If the remote ref

Documentation/user-manual.txt

@@ -2789,7 +2789,7 @@ A fast-forward looks something like this:
 
 In some cases it is possible that the new head will *not* actually be
 a descendant of the old head.  For example, the developer may have
-realized she made a serious mistake, and decided to backtrack,
+realized a serious mistake was made and decided to backtrack,
 resulting in a situation like:
 
 ................................................