changing 'advance' to 'advanced' in all cases as it makes more sense
updated first chapter and resized images
mistakenly forgot to add the new files
updating with new images from osm website, and using iD instead of potlatch 2
updating for changes and removing unnecessary material (preferences & plugins)
Merge pull request #131 from jeffhaack/gh-pages

Renaming advanced sections and updating beginner chapters in english