Fix broken doc links on the index page

Commit 017f99120b1 did not move documentation from dev/ to developer/.
The links on the index page were updated incorrectly.
This change reverts that and fixes the broken links.

Change-Id: Ia2f3703589c469bfc2a5204bdd3becc4b09efd0d
Merge "Fix broken doc links on the index page"