Extra information about git hook

versioning.md

@@ -8,14 +8,34 @@ This page describes how to keep track of all changes to calendars and
 address books with **git** (or any other version control system).
 
 The repository must be initialized by running `git init` in the file
-system folder. Internal files of Radicale can be excluded by creating the
+system folder. Its default location can be:
+
+```
+# cd /var/lib/radicale/collections # in case of globally-installed Radicale
+# git init
+```
+or
+```
+$ cd ~/.var/lib/radicale/collections  # in case of user-installed Radicale
+$ git init
+```
+
+Internal files of Radicale can be excluded by creating the
 file `.gitignore` with the following content:
 ```
 .Radicale.cache
 .Radicale.lock
 .Radicale.tmp-*
 ```
 
+Another git configuration issue, that must be performed is user.name and user.email 
+variables. You also need to do that only once per repository:
+
+```
+git config user.name "My Radicale User"
+git config user.email "[email protected]"
+``` 
+
 The configuration option `hook` in the `storage` section must be set to
 the following command:
 ```shell
@@ -24,3 +44,7 @@ git add -A && (git diff --cached --quiet || git commit -m "Changes by "%(user)s)
 
 The command gets executed after every change to the storage and commits
 the changes into the **git** repository.
+
+In case of problems, make sure you run radicale with ``--debug`` switch and 
+inspect the log output. For more information, please visit 
+[section on logging.]({{ site.baseurl }}/logging/) .