AQmon lite: bare bones example

[avaldebe]

AQmon development begun on nodemcu firmware version earlier than 0.9.5 20150318. The severe heap limitations shaped AQmon into small modules, that supported all the required sensors using as little heap as possible.

The current nodemcu firmware is quite good at keeping a "clean heap", and
the current version of the dev branch support all required sensors except the PMSx003.
As pointed out in #3, using a nodemcu-build firmware it is now possible to put all the required code into init.lua. AQmon lite will provide that bare bones example, so new users have a simpler starting point.

[avaldebe]

The nodemcu/lua branch of this project is dead.
The Arduino/c++ is still active.