Say "CERN" instead of "Cern"

It's an acronym, and this is how they style it on http://home.web.cern.ch/.
Refer consistently to the language as "Python"
Fix "differnt" typo
Fix "anythng" typo
Mark up more inline code
Merge pull request #5 from CodeClub/fix-typos

Fix a few minor typos in lesson 1