docs: add CONFIGURATION sections that fuzzy map to built-ins

Add a CONFIGURATION section to the documentation of various built-ins,
for those cases where the relevant config/NAME.txt doesn't map only to
one git-NAME.txt. In particular:

 * config/blame.txt: used by git-{blame,annotate}.txt. Since the
   git-annotate(1) documentation refers to git-blame(1) don't add a
   "CONFIGURATION" section to git-annotate(1), only to git-blame(1).

 * config/checkout.txt: maps to both git-checkout.txt and
   git-switch.txt (but nothing else).

 * config/init.txt: should be included in git-init(1) and
   git-clone(1).

 * config/column.txt: We should ideally mention the relevant subset of
   this in git-{branch,clean,status,tag}.txt, but let's punt on it for
   now. We will when we eventually split these sort of files into
   e.g. config/column.txt and
   config/column/{branch,clean,status,tag}.txt, with the former
   including the latter set.

Things that are being left out, and why:

 * config/{remote,remotes,credential}.txt: Configuration that affects
   how we talk to remote repositories is harder to untangle. We'll need
   to include some of this in git-{fetch,remote,push,ls-remote}.txt
   etc., but some of those only use a small subset of these
   options. Let's leave this for now.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-blame.txt

@@ -241,6 +241,12 @@ MAPPING AUTHORS
 
 See linkgit:gitmailmap[5].
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/blame.txt[]
 
 SEE ALSO
 --------

Documentation/git-branch.txt

@@ -336,6 +336,10 @@ CONFIGURATION
 `--list` is used or implied. The default is to use a pager.
 See linkgit:git-config[1].
 
+include::includes/cmd-config-section-rest.txt[]
+
+include::config/branch.txt[]
+
 EXAMPLES
 --------
 

Documentation/git-checkout.txt

@@ -600,6 +600,13 @@ $ edit frotz
 $ git add frotz
 ------------
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/checkout.txt[]
+
 SEE ALSO
 --------
 linkgit:git-switch[1],

Documentation/git-clone.txt

@@ -368,6 +368,8 @@ CONFIGURATION
 
 include::includes/cmd-config-section-all.txt[]
 
+include::config/init.txt[]
+
 include::config/clone.txt[]
 
 

Documentation/git-column.txt

@@ -74,6 +74,13 @@ v2.4.3  v2.4.4      v2.4.5      v2.4.6      v2.4.7
 v2.4.8  v2.4.9
 ------------
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/column.txt[]
+
 GIT
 ---
 Part of the linkgit:git[1] suite

Documentation/git-diff.txt

@@ -213,6 +213,13 @@ $ git diff -R                          <2>
     rewrites (very expensive).
 <2> Output diff in reverse.
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/diff.txt[]
+
 SEE ALSO
 --------
 diff(1),

Documentation/git-fetch.txt

@@ -285,6 +285,13 @@ linkgit:git-gc[1]).
 
 include::transfer-data-leaks.txt[]
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/fetch.txt[]
+
 BUGS
 ----
 Using --recurse-submodules can only fetch new commits in submodules that are

Documentation/git-init.txt

@@ -169,6 +169,13 @@ $ git commit    <3>
 <2> Add all existing files to the index.
 <3> Record the pristine state as the first commit in the history.
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/init.txt[]
+
 GIT
 ---
 Part of the linkgit:git[1] suite

Documentation/git-switch.txt

@@ -265,6 +265,13 @@ always create a new name for it (without switching away):
 $ git switch -c good-surprises
 ------------
 
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/checkout.txt[]
+
 SEE ALSO
 --------
 linkgit:git-checkout[1],