Documentation: match underline with the text

Even though AsciiDoc is more lenient when deciding if an underline
is for the contents on the previous line to find section headers, we
should match the length of them for other formatters to help them.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/git-bisect.txt

@@ -167,7 +167,7 @@ Then compile and test the chosen revision, and afterwards mark
 the revision as good or bad in the usual manner.
 
 Bisect skip
-~~~~~~~~~~~~
+~~~~~~~~~~~
 
 Instead of choosing by yourself a nearby commit, you can ask Git
 to do it for you by issuing the command:

Documentation/git-remote.txt

 git-remote(1)
-============
+=============
 
 NAME
 ----

Documentation/git-upload-archive.txt

 git-upload-archive(1)
-====================
+=====================
 
 NAME
 ----

Documentation/gitrevisions.txt

 gitrevisions(7)
-================
+===============
 
 NAME
 ----

Documentation/urls-remotes.txt

@@ -36,7 +36,7 @@ The `<pushurl>` is used for pushes only. It is optional and defaults
 to `<url>`.
 
 Named file in `$GIT_DIR/remotes`
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 You can choose to provide the name of a
 file in `$GIT_DIR/remotes`.  The URL