README.rst: mention the intersphinx directives
migrate section Editorial Policy into the guide
move section on using markup
move section on using github to contribute
remove the section on figures from the README
tweaking the README for better inclusion
replace semicolon with period, looks less awkward on github
include the link to generated HTML
Merge branch 'upgrade/contributing'

* upgrade/contributing:
  include the link to generated HTML
  replace semicolon with period, looks less awkward on github
  tweaking the README for better inclusion
  remove the section on figures from the README
  move section on using github to contribute
  move section on using markup
  migrate section Editorial Policy into the guide
  README.rst: mention the intersphinx directives