chore: update link to upgrade instructions (angular#1106)

Link was to header in changelog but content is in the readme

Author: aciccarello

CHANGELOG.md

@@ -1,4 +1,4 @@
-## Always follow the [upgrade guide](https://github.com/angular/angular-cli/blob/master/CHANGELOG.md#updating-angular-cli) when upgrading to a new version. The changelog does not list breaking changes that are fixed via the update procedure.
+## Always follow the [upgrade guide](https://github.com/angular/angular-cli#updating-angular-cli) when upgrading to a new version. The changelog does not list breaking changes that are fixed via the update procedure.
 
 <a name="1.0.0-beta.6"></a>
 # 1.0.0-beta.6 (2016-06-13)
@@ -32,4 +32,4 @@
 - `ng build -prod` fails on mobile projects due to missing vendor file (https://github.com/angular/angular-cli/issues/847).
 - Github deploy to user pages doesn't use correct base href (https://github.com/angular/angular-cli/pull/965).
 - `ng test` on windows hits the file discriptor limit (https://github.com/angular/angular-cli/issues/977).
-- `ng serve/build/test` need admin elevation on Windows (https://github.com/angular/angular-cli/issues/641).
+- `ng serve/build/test` need admin elevation on Windows (https://github.com/angular/angular-cli/issues/641).