update README.md
fixes gutters on mobile (again), adds style to number callouts on main page
fixes alignment in featured image content, fixes footer spacing, styles community page, styles get involved
fixes submit button on mobile (now hidden under hamburger menu)
Merge pull request #9 from KHarshawat/kavi-mobile-style

Kavi mobile style
Merge branch 'gh-pages' of github.com:KHarshawat/market-street-proto-fest into gh-pages