fixes #169(added favicon,meta and og tags)
fixes #169(added favicon,meta and og tags)

dpshelio/openastronomy.github.io,OpenAstronomy/openastronomy.github.io,dpshelio/openastronomy.github.io,dpshelio/openastronomy.github.io,OpenAstronomy/openastronomy.github.io,Cadair/openastronomy.github.io,Cadair/openastronomy.github.io,OpenAstronomy/openastronomy.github.io,Cadair/openastronomy.github.io