adds stats documentation
adds text to docs
finishes docs about  dissolving geometries
adds code evolution to stats doc
styles stats.md
removes queries titles
adds doc for marine intersection
adds marine intersection, dissoling geometries and stats calculator docs
adds country_statistics calculation docs
finishes stats_calculator docs
new file structure for stats docs
reviews dissolving_geometries and stats.md
reviews marine_intersection.md
adds mention to indices and adapts stats.md original doc
Merge branch 'master' of github.com:unepwcmc/ProtectedPlanet into stats_docs
fixes typos
Wrap to 80 chars
Merge pull request #101 from unepwcmc/stats_docs

Stats docs