No Favicon support for website

**I'm submitting a ...**  (check one with "x")
- [x] bug report
- [ ] feature request

**Description**:

There's a favicon for cosmos-search but it's not showing up on the website.  It has to be added. 

**Expected Behavior**:

Show OpenGenus logo as favicon.

**Would you like to work on this issue?**
- [ ] Yes
- [x] No