Describe commit message settings for IntelliJ

Change-Id: Ieaf7432aca8a8abe1adf560381c4f2c65a35cfff

Documentation/dev-intellij.txt

diff --git a/Documentation/dev-intellij.txt b/Documentation/dev-intellij.txt
index ae2dd4e..8f5b4d7 100644
--- a/Documentation/dev-intellij.txt
+++ b/Documentation/dev-intellij.txt
@@ -81,6 +81,26 @@
 . Select *File Header*.
 . Remove the template code in the right editor.
 
+=== Commit message
+To simplify the creation of commit messages which are compliant with the
+<<dev-contributing#commit-message,Commit Message>> format, do the following:
+
+. Go to *File -> Settings -> Version Control*.
+. Check *Commit message right margin (columns)*.
+. Make sure that 72 is specified as value.
+. Check *Wrap when typing reaches right margin*.
+
+In addition, you should follow the instructions of
+<<dev-contributing#git_commit_settings,this section>> (if you haven't
+done so already):
+
+* Install the Git hook for the `Change-Id` line.
+* Set up the HTTP access.
+
+Setting up the HTTP access will allow you to commit changes via IntelliJ without
+specifying your credentials. The Git hook won't be noticeable during a commit
+as it's executed after the commit dialog of IntelliJ was closed.
+
 == Run configurations
 Run configurations can be accessed on the toolbar. To edit them or add new ones,
 choose *Edit Configurations* on the drop-down list of the run configurations