META: Add/rescale headings for activities and resources page

Some activities and resources have headings while others do not. It should have to indicate clearly which activity/resource you are currently in. Please refer to the screenshot for reference.

Activities that need headings particularly h2:

1. Book
2. Choice
3. Forum
4. Glossary
5. Survey
6. Wiki
7. ...

All headings should be at the top most of the content page.

Please note: this meta is only focusing on adding/fixing the heading level and layout for the page. Other issues such as block header, content's font size, layout, positioning, etc. will not be fixed through this meta. We (Barbara and I) have plan to address those issues right after we are done fixing the page heading. For now, we are only focusing on heading. Thanks.

Documentation page for HTML Guidelines: http://docs.moodle.org/dev/HTML_Guidelines