feat(core): add tree.messages array and tree.options

a way to communicate between plugins

packages/bbob-core/src/index.js

@@ -30,6 +30,8 @@ export default function bbob(plugs) {
       // raw tree before modification with plugins
       const raw = tree;
 
+      tree.messages = [];
+      tree.options = options;
       tree.walk = walk;
       tree.match = match;