docs: sort configuration variable groupings alphabetically

By and large, variable groupings in Documentation/config.txt are sorted
alphabetically, though a few are not. Those outliers make it more
difficult to find a specific grouping when quickly running an eye over
the list to locate a variable of interest. Address this shortcoming by
sorting the groupings alphabetically.

NOTE: This change only sorts the top-level groupings (i.e. "core.*"
comes after "completion.*"); it does not touch the ordering of variables
within each group since variables within individual groups might
intentionally be ordered in some other fashion (such as
most-common-first or most-important-first).

Reported-by: Bruno Haible <[email protected]>
Signed-off-by: Eric Sunshine <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: sunshineco

Documentation/config.txt

@@ -369,20 +369,18 @@ inventing new variables for use in your own tool, make sure their
 names do not conflict with those that are used by Git itself and
 other popular tools, and describe them in your documentation.
 
-include::config/advice.txt[]
-
-include::config/attr.txt[]
-
-include::config/core.txt[]
-
 include::config/add.txt[]
 
+include::config/advice.txt[]
+
 include::config/alias.txt[]
 
 include::config/am.txt[]
 
 include::config/apply.txt[]
 
+include::config/attr.txt[]
+
 include::config/blame.txt[]
 
 include::config/branch.txt[]
@@ -405,10 +403,12 @@ include::config/commit.txt[]
 
 include::config/commitgraph.txt[]
 
-include::config/credential.txt[]
-
 include::config/completion.txt[]
 
+include::config/core.txt[]
+
+include::config/credential.txt[]
+
 include::config/diff.txt[]
 
 include::config/difftool.txt[]
@@ -421,10 +421,10 @@ include::config/feature.txt[]
 
 include::config/fetch.txt[]
 
-include::config/format.txt[]
-
 include::config/filter.txt[]
 
+include::config/format.txt[]
+
 include::config/fsck.txt[]
 
 include::config/fsmonitor--daemon.txt[]
@@ -435,10 +435,10 @@ include::config/gitcvs.txt[]
 
 include::config/gitweb.txt[]
 
-include::config/grep.txt[]
-
 include::config/gpg.txt[]
 
+include::config/grep.txt[]
+
 include::config/gui.txt[]
 
 include::config/guitool.txt[]
@@ -519,10 +519,10 @@ include::config/splitindex.txt[]
 
 include::config/ssh.txt[]
 
-include::config/status.txt[]
-
 include::config/stash.txt[]
 
+include::config/status.txt[]
+
 include::config/submodule.txt[]
 
 include::config/tag.txt[]