fixes #677 - mistype in docs/quickstart
Add closing html tag
Move docs explaining instantiating Flask
Put the link to Flask class docs at the end.
Remove comma.
Update css.rst

Improved consistency: lower cased all hexadecimal descriptions of colors.
Merge pull request #689 from OrangeTux/patch-2

Update css.rst
Merge pull request #683 from alexcouper/master

Tiny changes to docs
Merge pull request #681 from dmizelle/docs-quickstart

fixes #677 - mistype in docs/quickstart