fic: xontext add description

packages/behavior/types.hooks.js

@@ -23,7 +23,7 @@ export function behaviorTypes() {
         children: {
           add: {
             type: 'void',
-            label: 'Add $2 as $1.',
+            label: 'Add $2 as $1 with type of $3.',
             args: [
               ['key', {
                 type: 'string',
@@ -31,6 +31,9 @@ export function behaviorTypes() {
               ['value', {
                 type: 'any',
               }],
+              ['type', {
+                type: 'string',
+              }],
             ],
           },
         },