docs/config-common: add language specifications to ini code blocks

This enables the possibility of syntax highlighting.

Change-Id: I9f99dfaf1e756d577d4373e73abbdac1bb1c78cd

src/main/resources/Documentation/config-common.md

diff --git a/src/main/resources/Documentation/config-common.md b/src/main/resources/Documentation/config-common.md
index 109aba4..dd16fb6 100644
--- a/src/main/resources/Documentation/config-common.md
+++ b/src/main/resources/Documentation/config-common.md
@@ -22,7 +22,7 @@
 
 So for example having
 
-```
+```ini
 [commentlink "@PLUGIN@"]
     match = [Bb][Uu][Gg][ ]*([1-9][0-9]*)
     html = "<a href=\"http://my.issure.tracker.example.org/show_bug.cgi?id=$1\">(bug $1)</a>"
@@ -57,7 +57,7 @@
 
 Example:
 
-```
+```ini
 [plugin "@PLUGIN@"]
     association = MANDATORY
 ```
@@ -81,7 +81,7 @@
 for a project the project must have the following entry in its
 `project.config` file in the `refs/meta/config` branch:
 
-```
+```ini
   [plugin "@PLUGIN@"]
     enabled = true
 ```
@@ -115,7 +115,7 @@
 E.g. to limit the issue tracker system integration to the `master`
 branch and all stable branches the following could be configured:
 
-```
+```ini
   [plugin "@PLUGIN@"]
     enabled = true
     branch = refs/heads/master
@@ -132,7 +132,7 @@
 must have the following entry in its `project.config` file in the
 `refs/meta/config` branch:
 
-```
+```ini
   [plugin "@PLUGIN@"]
     its-project = manhattan-project
 ```