[PATCH] config: fix commit-graph related config docs

[Derrick Stolee <dstolee@microsoft.com>]

The core.commitGraph config setting was accidentally removed from
the config documentation. In that same patch, the config setting
that writes a commit-graph during garbage collection was incorrectly
written to the doc as "gc.commitGraph" instead of "gc.writeCommitGraph".

Reported-by: Szeder Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---

Szeder reported this in [1] and I forgot until now to come back to it.

[1] https://public-inbox.org/git/20180803093909.2853-1-szeder.dev@gmail.com/

 Documentation/config.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 1c42364988..f846543414 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -917,7 +917,11 @@ core.notesRef::
 This setting defaults to "refs/notes/commits", and it can be overridden by
 the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
 
-gc.commitGraph::
+core.commitGraph::
+	Enable git commit graph feature. Allows reading from the
+	commit-graph file.
+
+gc.writeCommitGraph::
 	If true, then gc will rewrite the commit-graph file when
 	linkgit:git-gc[1] is run. When using linkgit:git-gc[1]
 	'--auto' the commit-graph will be updated if housekeeping is

base-commit: 7e8bfb0412581daf8f3c89909f1d37844e8610dd
-- 
2.19.0.rc0