Cleaned up readme.

README.md

@@ -60,12 +60,26 @@ console.info(obj); // { foo: { bar: ['a', 'b', 'c', 'd'] } }
 You can also directly create `GawkObject` and `GawkArray` objects:
 
 ```javascript
-import gawk, { GawkArray, GawkObject } from 'gawk';
+import { GawkArray, GawkObject } from 'gawk';
 
 const obj = new GawkObject({ foo: 'bar' });
 const arr = new GawkArray('a', 'b', 'c');
 ```
 
+## Upgrading from v1
+
+Gawk v2 has dropped all gawk data types except `GawkArray` and `GawkObject`.
+
+Since Gawk v2 uses ES6 Proxies, you no longer need to call `obj.get()`,
+`obj.set()`, `obj.delete()`, etc.
+
+Methods `obj.watch()`, `obj.merge()`, and `obj.mergeDeep()` have moved to
+`gawk.watch()`, `gawk.merge()`, and `gawk.mergeDeep()`. The first argument must
+be a gawk object.
+
+Gawk v2 no longer hashes values. This means speed. Gawk v2 is about 19 times
+faster than v1.
+
 ## License
 
 (The MIT License)