Merge pull request #44 from sabas/gh-pages

Expanding the shapefile paragraph
Add scales image
Merge branch 'gh-pages' of github.com:tmcw/mapschool into gh-pages
Rebuild
Add favicon. Fixes #39
late night.
Add section on the shape of the earth.
In-content permalinks
Earth shapes graphic
Added context for definition of a 'map' - computer maps have a short history.
Fix typo: unnecessary capitalization
Clarified and expanded shapefile explanation.
Topology is not always about 'touching'
Drawbacks of GeoJSON
Added 'deforestation' to what infra-red is used to map.
Pluralize "files" (minor grammar tweak)
Merge pull request #48 from daguar/patch-1

Pluralize "files" (minor grammar tweak)
Rebuild generated
Clarify that README is core text in CONTRIBUTING

Just wanted to add some quick clarifying language in CONTRIBUTING.md so that no one makes the same mistake I did in #47.
Merge pull request #49 from daguar/patch-1

Clarify that README is core text in CONTRIBUTING