minor spellchecks and re-organizing
added intro and license text for pdf generation
Merge branch 'lgutrainmat' of https://github.com/feyeandal/learnosm into lgutrainmat
Merge branch 'lgutrainmat' of https://github.com/maning/learnosm into lgutrainmat
markdown to pdf folder
Added cover
remove folder
Md to PDF
added intro