Add Azure Pipelines documentation (#326)

Author: daveneeley

README.md

@@ -127,6 +127,7 @@ Generally, when fiddling with this plugin, you may want to use something like [R
 
 Here are some guides on how to use the plugin with different systems. Feel free to add guides through pull requests to this repo!
 
+ * [Azure Pipelines](https://github.com/tomasbjerre/pull-request-notifier-for-bitbucket/blob/master/README_azurepipelines.md)
  * [HipChat](https://github.com/tomasbjerre/pull-request-notifier-for-bitbucket/blob/master/README_hipchat.md)
  * [Jenkins](https://github.com/tomasbjerre/pull-request-notifier-for-bitbucket/blob/master/README_jenkins.md)
  * [Slack](https://github.com/Igogrek/bitbucket-slack-notifier)

README_azurepiplines.md

@@ -0,0 +1,18 @@
+# Azure Pipelines
+
+Here is how to integrate with Azure Pipelines (VSTS).
+
+* URL should be set to `https://<account name>.visualstudio.com/<project name>/_apis/build/builds?api-version=5.0` or `https://dev.azure.com/<account name>/<project name>/_apis/build/builds?api-version=5.0`
+* Method should be **POST**
+* Post content should be:
+```
+{
+        "definition": {
+            "id": <build definitionId from url>
+        }
+}
+```
+* Encode post content as JSON
+* In **Headers** add "Content-Type" with value "application/json"
+
+Additional data can be sent in the post. See [Azure API Docs](https://docs.microsoft.com/en-us/rest/api/azure/devops/build/Builds/Queue?view=azure-devops-rest-5.0) for more info. The build history will state 'Manual build for <owner of personal access token>' for each build triggered by this method.