Documentation: edit awkward references to git merge-recursive

A few places in the documentation referred to the "`recursive` strategy"
using the phrase "`git merge-recursive`", suggesting that it was forking
subprocesses to call a toplevel builtin.  Perhaps that was relevant to
when rebase was a shell script, but it seems like a rather indirect way
to refer to the `recursive` strategy.  Simplify the references.

Signed-off-by: Elijah Newren <[email protected]>

Author: newren

Documentation/git-rebase.txt

@@ -354,9 +354,8 @@ See also INCOMPATIBLE OPTIONS below.
 
 -s <strategy>::
 --strategy=<strategy>::
-	Use the given merge strategy.
-	If there is no `-s` option 'git merge-recursive' is used
-	instead.  This implies --merge.
+	Use the given merge strategy, instead of the default
+	`recursive`.  This implies `--merge`.
 +
 Because 'git rebase' replays each commit from the working branch
 on top of the <upstream> branch using the given strategy, using

Documentation/merge-options.txt

@@ -112,8 +112,8 @@ With --squash, --commit is not allowed, and will fail.
 	Use the given merge strategy; can be supplied more than
 	once to specify them in the order they should be tried.
 	If there is no `-s` option, a built-in list of strategies
-	is used instead ('git merge-recursive' when merging a single
-	head, 'git merge-octopus' otherwise).
+	is used instead (`recursive` when merging a single head,
+	`octopus` otherwise).
 
 -X <option>::
 --strategy-option=<option>::

Documentation/merge-strategies.txt

@@ -51,10 +51,11 @@ patience;;
 	See also linkgit:git-diff[1] `--patience`.
 
 diff-algorithm=[patience|minimal|histogram|myers];;
-	Tells 'merge-recursive' to use a different diff algorithm, which
-	can help avoid mismerges that occur due to unimportant matching
-	lines (such as braces from distinct functions).  See also
-	linkgit:git-diff[1] `--diff-algorithm`.
+	Use a different diff algorithm while merging, which can help
+	avoid mismerges that occur due to unimportant matching lines
+	(such as braces from distinct functions).  See also
+	linkgit:git-diff[1] `--diff-algorithm`.  Defaults to the
+	`diff.algorithm` config setting.
 
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