doc: fix repeated words

Inspired by 21416f0a07 ("restore: fix typo in docs", 2019-08-03), I ran
"git grep -E '(\b[a-zA-Z]+) \1\b' -- Documentation/" to find other cases
where words were duplicated, e.g. "the the", and in most cases removed
one of the repeated words.

There were many false positives by this grep command, including
deliberate repeated words like "really really" or valid uses of "that
that" which I left alone, of course.

I also did not correct any of the legitimate, accidentally repeated
words in old RelNotes.

Signed-off-by: Mark Rushakoff <mark.rushakoff@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config/color.txt

@@ -14,7 +14,7 @@ color.blame.highlightRecent::
 +
 This setting should be set to a comma-separated list of color and date settings,
 starting and ending with a color, the dates should be set from oldest to newest.
-The metadata will be colored given the colors if the the line was introduced
+The metadata will be colored given the colors if the line was introduced
 before the given timestamp, overwriting older timestamped colors.
 +
 Instead of an absolute timestamp relative timestamps work as well, e.g.

Documentation/config/stash.txt

@@ -4,7 +4,7 @@ stash.useBuiltin::
        the built-in rewrite of it in C.
 +
 The C rewrite is first included with Git version 2.22 (and Git for Windows
-version 2.19). This option serves an an escape hatch to re-enable the
+version 2.19). This option serves as an escape hatch to re-enable the
 legacy version in case any bugs are found in the rewrite. This option and
 the shell script version of linkgit:git-stash[1] will be removed in some
 future release.