Add favicon

Summary:
Source media file for favicon:
https://commons.wikimedia.org/wiki/File:Eglide-logo.svg

Logo authored by @rama.

License: CC-BY 4.0, CC-BY-SA 3.0 France, or CeCILL.

Generator:
http://realfavicongenerator.net/

Test Plan: Tested with a minimal design

Reviewers: dereckson

Subscribers: rama

Differential Revision: https://devcentral.nasqueron.org/D675