small tweaks to docs

docs/redraw.md

@@ -1,11 +1,11 @@
 # redraw()
 
-- [API](#api)
+- [Signature](#signature)
 - [How it works](#how-it-works)
 
 ---
 
-### API
+### Signature
 
 `m.redraw()`
 
@@ -19,6 +19,6 @@ Argument    | Type                 | Required | Description
 
 When callbacks outside of Mithril run, you need to notify Mithril's rendering engine that a redraw is needed. External callbacks could be `setTimeout`/`setInterval`/`requestAnimationFrame` callbacks, web socket library callbacks, event handlers in jQuery plugins, third party XHR request callbacks, etc.
 
-To trigger a redraw, call `m.redraw()`
+To trigger a redraw, call `m.redraw()`. Note that `m.redraw` only works if you used `m.mount` or `m.route`. If you rendered via `m.render`, you should use `m.render` to redraw.
 
 You should not call m.redraw from a [lifecycle method](lifecycle-methods.md). Doing so will result in undefined behavior.