[docs] updated vm functionality

docs/vm_functionality.md

@@ -3,11 +3,19 @@ The VM provides some utilits needed for DApp development.
 ## ethereumAddress
 This is a constant representing the ethereum address of the user
 
-## renderMessage
-
 ## renderModal
+`renderModal(uiID <string>, layout <string>, callback <string>)` the uiID must be created with the `newModalUIID` method.
+The callback will be called once the modal got rendered.
 
 ## sendETHTransaction
+`sendETHTransaction(transactionParams <object>, callback <function>)` will send an ethereum transaction.
+The transaction params should look like this:
+
+- `value` the value in wei
+- `to` should be an address
+- `data` can be the data to execute
+
+The callback will be called with an transaction object.
 
 ## sendMessage
 `sendMessage(chat <string>, payload <object>, callback <function>)` will send a message with the given parameters.
@@ -30,6 +38,7 @@ The modal ID can then be used to display a modal.
 
 ## db
 The database provides four methods:
+
 - `put(key <string>, value <string>, callback <function>)`
 - `get(key <string>, callback <function>)`
 - `has(key <string>, callback <function>)`