app: Document TODOs
doc: Move separate projects out of braindump, add notes on value prop

* http://github.com/jonnor/finito
Introspectable, testable, language-agnostic finite state machines

* http://github.com/jonnor/sensorblock
Generic smart sensor hardware for quick prototyping
Don't hook into npm install to build Node.js module, use make target instead

To rebuild the module before running tests, should use "make check".
Eventually this will all be integrated in grunt.
doc: Move related section from README to braindump