Simplify project doc templates

Remove the separate file that includes README.rst.

Fix up the title string generation at the top of index.rst.

Add default api.rst.

Remove virtualenvwrapper instructions from usage.rst since we don't need
those.

Add history.rst file.

Change-Id: Ieda600538c1868a64dd2fea7142e13ea3b846de5
Merge "Simplify project doc templates"