doc tweaks
direct to brew website for brew installation; add more explanation of cross-compiling
bump version: 0.0.36
Merge branch 'master' of github.com:ARMmbed/yotta into doc-improvements
add documentation on targets
Merge pull request #102 from autopulated/doc-improvements

Doc improvements
debugServer property instead of debug-server in target.json (be consistent about name style)
the command prompt was confusing in user-testing, simplify it
add module.json reference
formatting improvements
add target.json reference
Merge pull request #103 from autopulated/doc-improvements

Doc improvements
add linux installation docs; improve formatting of mac installation docs
Merge pull request #104 from autopulated/doc-improvements

add linux installation docs; improve formatting of mac installation docs