📚 Add current pitfalls to README

Author: leonardfactory

README.md

@@ -104,3 +104,21 @@ With `.babelrc`:
   ]
 }
 ```
+
+## Current Pitfalls
+
+- We cannot know if type annotations are just types (i.e. `IMyInterface`) or
+  concrete values (like classes, etc.). In order to resolve this, we emit the
+  following: `typeof Type === 'undefined' ? Object : Type`. The code has the
+  advantage of not throwing If you know a better
+  way to do this, let me know!
+- Parameter decorators are emitted right _after_ the `ClassDeclaration` node,
+  like:
+
+  ```js
+  let A = (/* ... */)
+  Inject()(A.prototype, 'methodName', 1);
+  ```
+
+  I'm not sure if this can cause issue with scoping, if you get in troubles with
+  this kind of decorators, please open an issue.