Documentation: Add commitmsg hook info

Currently, in the "Quick Get Started guide" there is no information
about the Change-Id or the commitmsg hook that generates the Change-Id.
This adds information about how to install the commitmsg hook to the
initial git repo.

Change-Id: I7eeb7abec8b009afb22fcd89e1b1d0d5d48527cf
Signed-off-by: Tyler Cipriani <tcipriani@wikimedia.org>
diff --git a/Documentation/install-quick.txt b/Documentation/install-quick.txt
index 7b80229..2503449 100644
--- a/Documentation/install-quick.txt
+++ b/Documentation/install-quick.txt
@@ -172,7 +172,14 @@
   user@host:~/demo-project$
 ----
 
-Then make a change to it and upload it as a reviewable change in Gerrit.
+Install the link:user-changeid.html[Change-Id commitmsg hook]
+
+----
+  scp -p -P 29418 user@localhost:hooks/commit-msg $(git rev-parse --git-dir)/hooks/
+----
+
+Then make a change to the repository and upload it as a reviewable change
+in Gerrit.
 
 ----
   user@host:~/demo-project$ date > testfile.txt