Update usage.md

docs/usage.md

@@ -81,6 +81,24 @@ Would end up like this:
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+An id attribute is also added to mermaid tags without one.	## Simple full example:
+
+### To enable click event and tags in nodes	
+
+In version 8.2 a security improvement was introduced. A `securityLevel` configuration was introduced which sets the level of trust to be used on the parsed diagrams.	
+
+* **true**: (default) tags in text are encoded, click functionality is disabled	
+* false: tags in text are allowed, click functionality is enabled	
+
+⚠️ **Note** : This changes the default behaviour of mermaid so that after upgrade to 8.2, if the `securityLevel` is not configured, tags in flowcharts are encoded as tags and clicking is prohibited.	
+
+If your application is taking resposibility for the diagram source security you can set the `securityLevel` accordingly. By doing this clicks and tags are again allowed.	
+
+```javascript	
+    mermaidAPI.initialize({	
+        securityLevel: 'loose'	
+    });	
+```	
 
 ## Notes: 
 An id attribute is also added to mermaid tags without one.