add alias description

Signed-off-by: Andreas Hechenberger <world@greenstation.de>

CONTRIBUTING.md

@@ -38,10 +38,10 @@ In some areas unit testing is hard (aka almost impossible) as of today - in thes
 ### Sign your work
 
 We use the Developer Certificate of Origin (DCO) as a additional safeguard
-for the Nextcloud project. This is a well established and widely used 
-mechanism to assure contributors have confirmed their right to license 
-their contribution under the project's license. 
-Please read [contribute/developer-certificate-of-origin][dcofile]. 
+for the Nextcloud project. This is a well established and widely used
+mechanism to assure contributors have confirmed their right to license
+their contribution under the project's license.
+Please read [contribute/developer-certificate-of-origin][dcofile].
 If you can certify it, then just add a line to every git commit message:
 
 ````
@@ -50,7 +50,9 @@ If you can certify it, then just add a line to every git commit message:
 
 Use your real name (sorry, no pseudonyms or anonymous contributions).
 If you set your `user.name` and `user.email` git configs, you can sign your
-commit automatically with `git commit -s`.
+commit automatically with `git commit -s`. You can also use git [aliases](https://git-scm.com/book/tr/v2/Git-Basics-Git-Aliases)
+like `git config --global alias.ci 'commit -s'`. Now you can commit with
+`git ci` and the commit will be signed.
 
 ### Apply a license