Breaking change announcements point to flutter-announce@ (#1596)

Author: Hixie

src/docs/resources/design-principles.md

@@ -111,7 +111,7 @@ To make a change that will require developers to change their code:
  1. File an issue or create a pull request with the `severe: API break`
     label.
 
- 2. Send an e-mail to <mailto:{{site.email}}> to socialize
+ 2. Send an e-mail to <mailto:[email protected]> to socialize
     your proposed change. The purpose of this e-mail is to see if you can
     get consensus around your change. **You are not telling people that
     the change will happen, you are asking them for permission.**
@@ -167,7 +167,7 @@ class FooInterface {
 ```
 
 If you use `@deprecated`, make sure to remember to actually remove the feature a few
-weeks later (after the next beta release), do not just leave it forever!
+months later (after the next stable release), do not just leave it forever!
 
 
 ### Google-only responsibilities