rename this tip to be less confusing

Using props to initialize state is completely fine; the issue is using state as a "cache" for values calculated based off of props. This title makes it more clear.

tips/10-props-in-getInitialState-as-anti-pattern.md

@@ -1,6 +1,6 @@
 ---
 id: props-in-getInitialState-as-anti-pattern
-title: Props in getInitialState Is an Anti-Pattern
+title: Using state to cache calculations is an antipattern
 layout: tips
 permalink: props-in-getInitialState-as-anti-pattern.html
 prev: componentWillReceiveProps-not-triggered-after-mounting.html
@@ -11,7 +11,7 @@ next: dom-event-listeners.html
 >
 > This isn't really a React-specific tip, as such anti-patterns often occur in code in general; in this case, React simply points them out more clearly.
 
-Using props, passed down from parent, to generate state in `getInitialState` often leads to duplication of "source of truth", i.e. where the real data is. Whenever possible, compute values on-the-fly to ensure that they don't get out of sync later on and cause maintenance trouble.
+Using state to cache values calculated from props (for example in `getInitialState`) often leads to duplication of "source of truth", i.e. where the real data is. Whenever possible, compute values on-the-fly to ensure that they don't get out of sync later on and cause maintenance trouble.
 
 Bad example: