Update README.md

- KILL WITH FIRE the dead links to docs.cloudfoundry.com.
- Remove dead link spiff.cfapp.io.
- Fix link to sample manifest.
- Fix typos, grammar, and unclear wording.
- Remove section on creating a release.
- Switch table of CF components to markdown instead of HTML. Drawback is that the edit mode on GitHub will look terrible unless line wrap mode is set to no wrap.
- Update links to components.

CF Community Pair (@chou & @jfoley)