[PATCH 2/4] gc docs: include the "gc.*" section from "config" in "gc"

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Rather than duplicating the documentation for the various "gc" options
let's include the "gc" docs from git-config. They were mostly better
already, and now we don't have the same docs in two places with subtly
different wording.

In the cases where the git-gc(1) docs were saying something the "gc"
docs in git-config(1) didn't cover move the relevant section over to
the git-config(1) docs.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 Documentation/config/gc.txt | 12 +++++++
 Documentation/git-gc.txt    | 65 +++----------------------------------
 2 files changed, 16 insertions(+), 61 deletions(-)

diff --git a/Documentation/config/gc.txt b/Documentation/config/gc.txt
index c6fbb8a96f9..a834a801cd6 100644
--- a/Documentation/config/gc.txt
+++ b/Documentation/config/gc.txt
@@ -2,11 +2,17 @@ gc.aggressiveDepth::
 	The depth parameter used in the delta compression
 	algorithm used by 'git gc --aggressive'.  This defaults
 	to 50.
++
+See the documentation for the `--depth` option in
+linkgit:git-repack[1] for more details.
 
 gc.aggressiveWindow::
 	The window size parameter used in the delta compression
 	algorithm used by 'git gc --aggressive'.  This defaults
 	to 250.
++
+See the documentation for the `--window` option in
+linkgit:git-repack[1] for more details.
 
 gc.auto::
 	When there are approximately more than this many loose
@@ -94,6 +100,12 @@ gc.<pattern>.reflogExpireUnreachable::
 	With "<pattern>" (e.g. "refs/stash")
 	in the middle, the setting applies only to the refs that
 	match the <pattern>.
++
+These types of entries are generally created as a result of using `git
+commit --amend` or `git rebase` and are the commits prior to the amend
+or rebase occurring. Since these changes are not part of the current
+project history most users will want to expire them sooner, which is
+why the default is more aggressive than `gc.reflogExpire`.
 
 gc.rerereResolved::
 	Records of conflicted merge you resolved earlier are
diff --git a/Documentation/git-gc.txt b/Documentation/git-gc.txt
index cc82971022e..9edf4e465b4 100644
--- a/Documentation/git-gc.txt
+++ b/Documentation/git-gc.txt
@@ -29,8 +29,7 @@ You should only need to run `git gc` manually when adding objects to a
 repository without regularly running such porcelain commands. Another
 use-case is wanting to do a one-off repository optimization.
 
-If you know what you're doing and all you want is to disable automatic
-runs, do:
+If you know what you're doing and want to disable automatic runs, do:
 
 ----------------------
 $ git config --global gc.auto 0
@@ -103,66 +102,10 @@ be performed as well.
 CONFIGURATION
 -------------
 
-The optional configuration variable `gc.reflogExpire` can be
-set to indicate how long historical entries within each branch's
-reflog should remain available in this repository.  The setting is
-expressed as a length of time, for example '90 days' or '3 months'.
-It defaults to '90 days'.
-
-The optional configuration variable `gc.reflogExpireUnreachable`
-can be set to indicate how long historical reflog entries which
-are not part of the current branch should remain available in
-this repository.  These types of entries are generally created as
-a result of using `git commit --amend` or `git rebase` and are the
-commits prior to the amend or rebase occurring.  Since these changes
-are not part of the current project most users will want to expire
-them sooner.  This option defaults to '30 days'.
-
-The above two configuration variables can be given to a pattern.  For
-example, this sets non-default expiry values only to remote-tracking
-branches:
-
-------------
-[gc "refs/remotes/*"]
-	reflogExpire = never
-	reflogExpireUnreachable = 3 days
-------------
-
-The optional configuration variable `gc.rerereResolved` indicates
-how long records of conflicted merge you resolved earlier are
-kept.  This defaults to 60 days.
-
-The optional configuration variable `gc.rerereUnresolved` indicates
-how long records of conflicted merge you have not resolved are
-kept.  This defaults to 15 days.
-
-The optional configuration variable `gc.packRefs` determines if
-'git gc' runs 'git pack-refs'. This can be set to "notbare" to enable
-it within all non-bare repos or it can be set to a boolean value.
-This defaults to true.
-
-The optional configuration variable `gc.writeCommitGraph` determines if
-'git gc' should run 'git commit-graph write'. This can be set to a
-boolean value. This defaults to false.
-
-The optional configuration variable `gc.aggressiveWindow` controls how
-much time is spent optimizing the delta compression of the objects in
-the repository when the --aggressive option is specified.  The larger
-the value, the more time is spent optimizing the delta compression.  See
-the documentation for the --window option in linkgit:git-repack[1] for
-more details.  This defaults to 250.
-
-Similarly, the optional configuration variable `gc.aggressiveDepth`
-controls --depth option in linkgit:git-repack[1]. This defaults to 50.
-
-The optional configuration variable `gc.pruneExpire` controls how old
-the unreferenced loose objects have to be before they are pruned.  The
-default is "2 weeks ago".
-
-Optional configuration variable `gc.worktreePruneExpire` controls how
-old a stale working tree should be before `git worktree prune` deletes
-it. Default is "3 months ago".
+The below documentation is the same as what's found in
+linkgit:git-config[1]:
 
+include::config/gc.txt[]
 
 NOTES
 -----
-- 
2.21.0.360.g471c308f928