Capitalization of Shiny

[mine-cetinkaya-rundel]

It's shiny when it's the package, but Shiny when it's a "Shiny app".

This issue is to remember to do a search for " shiny" and where appropriate replace it with " Shiny" periodically / before writing is done.

[hadley]

I'm practicing this capitalisation now, and we'll do a final pass in proof reading.