documentation: wording improvements

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Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/howto/maintain-git.txt

@@ -104,7 +104,7 @@ by doing the following:
    files in mbox format).
 
  - Write his own patches to address issues raised on the list but
-   nobody has stepped up solving.  Send it out just like other
+   nobody has stepped up to solve.  Send it out just like other
    contributors do, and pick them up just like patches from other
    contributors (see above).
 
@@ -417,7 +417,7 @@ are merged together, the reference to the variable newly added by
 the latter topic will still use the old name in the result.
 
 The Meta/Reintegrate script that is used by redo-jch and redo-seen
-scripts implements a crude but usable way to work this issue around.
+scripts implements a crude but usable way to work around this issue.
 When the script merges branch $X, it checks if "refs/merge-fix/$X"
 exists, and if so, the effect of it is squashed into the result of
 the mechanical merge.  In other words,

Documentation/howto/using-merge-subtree.txt

@@ -11,7 +11,7 @@ Message-ID: <BAYC1-PASMTP12374B54BA370A1E1C6E78AE4E0@CEZ.ICE>
 How to use the subtree merge strategy
 =====================================
 
-There are situations where you want to include contents in your project
+There are situations where you want to include content in your project
 from an independently developed project. You can just pull from the
 other project as long as there are no conflicting paths.