Add more migration notes (#1075)

docs/v1.x-migration.md

@@ -5,6 +5,8 @@ Migrating from `v0.2.x` to `v1.x`
 
 - [`config` function](#config-function)
 - [Cancelling redraw from event handlers](#cancelling-redraw-from-event-handlers)
+- [Component `controller` function](#component-controller-function)
+- [Passing components to `m()`](#passing-components-to-m)
 
 ## `config` function
 
@@ -67,3 +69,69 @@ m("div", {
     }
 })
 ```
+
+## Component `controller` function
+
+In `v1.x` there is no more `controller` property in components, use `oninit` instead.
+
+### `v0.2.x`
+
+```js
+m.mount(document.body, {
+    controller : function() {
+        var ctrl = this;
+        
+        ctrl.fooga = 1;
+    },
+    
+    view : function(ctrl) {
+        return m("p", ctrl.fooga);
+    }
+});
+```
+
+### `v1.x`
+
+```js
+m.mount(document.body, {
+    oninit : function(vnode) {
+        vnode.state.fooga = 1;
+    },
+    
+    view : function(vnode) {
+        return m("p", vnode.state.fooga);
+    }
+});
+
+// OR
+
+m.mount(document.body, {
+    oninit : function(vnode) {
+        var ctrl = this;  // this is bound to vnode.state by default
+        
+        ctrl.fooga = 1;
+    },
+    
+    view : function(vnode) {
+        var ctrl = this; // this is bound to vnode.state by default
+        
+        return m("p", ctrl.fooga);
+    }
+});
+```
+
+## Passing components to `m()`
+
+In `v0.2.x` you could pass components as the second argument of `m()` w/o any wrapping required. To help with consistency in `v1.x` they must always be wrapped with a `m()` invocation.
+
+### `v0.2.x`
+
+```js
+m("div", <component>);
+```
+
+### `v1.x`
+
+```js
+m("div", m(<component>));
+```