Update api.md

docs/api.md

@@ -45,7 +45,21 @@ The messageData object will be converted to JSON and passed as a parsed object t
 
 ### events
 
+* `fileOpened`
+    * Called when a file has been succesfully opened 
+    * Event data:
+        * `file` - the absolute path to the file
+        * `content` - a brief content description of the file
+* `fileSaved`
+    * Called when a file has been succesfully saved
+    * Event data:
+        * `file` - the absolute path to the file
+
 ## Frontend
 
 ### events
+* `formulaRender`
+    * Called when a formula is sent to the renderer
+    * Event data:
+        * `latex` - the LaTeX input, **can be modified**