#481 Adding documentation on how to apply yaml files directly (ad hoc)

Closes #481

Author: ghenzler

docs/ApplyConfig.md

@@ -141,5 +141,31 @@ NOTE: Usually it is better to rely on the install hook and manual executions via
 The upload listener service requires the `AC Tool Installation Service` (PID `biz.netcentric.cq.tools.actool.impl.AcInstallationServiceImpl`) to be configured correctly, i.e. its configuration path must point to the nodes containing the `YAML` files.
 <img src="images/installation-service.png">
 
+### Ad hoc installation of small fragments
+
+Generally it is best practice to keep the yaml files in source control and only use one of the above methods to trigger the installation of those files. 
+However for some support scenarios it can be useful to be able to apply small yaml fragments directly. This can be achieved by using the following 
+groovy script (using the [AEM Groovy Console](https://github.com/icfnext/aem-groovy-console)):
+
+```
+import static org.apache.jackrabbit.commons.JcrUtils.*
+import static org.apache.commons.io.IOUtils.*
+import biz.netcentric.cq.tools.actool.api.AcInstallationService
+def runAcTool(adhocFolder, adhocFile, yaml) {
+    putFile(getOrCreateByPath(adhocFolder, "nt:folder", session), adhocFile, "text/yaml", toInputStream(yaml)); session.save();
+    return getService(AcInstallationService.class).apply(adhocFolder)
+}
+
+runAcTool("/tmp/actool-adhoc", "actool.yaml", """
+    
+- user_config:
+    - test-user:
+       - name: "My test user"
+         path: /home/users/testusers
+
+""")
+```
+
+As for any executions, the log of ad hoc installations are found underneath `/var/statistics/achistory`.