Cleanup on README and boards_manager#1693

Merged

me-no-dev merged 9 commits intoespressif:masterfrom

lbernstone:pr1

Jul 30, 2018

Commits on Jul 8, 2018

Added instructions for installation with boards manager (stolen directly from esp8266)
lbernstone
committed

Commits on Jul 12, 2018

changed to production link instead of dev
lbernstone
committed

Commits on Jul 14, 2018

Merge branch 'master' of https://github.com/espressif/arduino-esp32 into pr1
lbernstone
committed

Commits on Jul 25, 2018

Commits on Jul 27, 2018

Commits on Jul 28, 2018