docs: Clean up doc generation
docs: Clean up doc generation

The "globals" section on the right hand side of the generated docs was
full of useless garbage.  Similarly, the main page of the docs had a
footer listing a few random files that use @fileoverview in them.
Both of these have been removed from the jsdoc template.

Change-Id: I6d549274cb82df997da8a2e5abfad5669146ad9f

shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player