WL-3478 Announcements Email contains unreplaced parameter and is suboptimal

2 things:
   1. For HTML email content, we were missing out the service title.
   2. For text content, we were putting in the base URL rather than the site's hierarchy URL.
Merge pull request #4 from ox-it/WL-3478

WL-3478 Announcements Email contains unreplaced parameter