Fix typo and Markdown link syntax
Use a colon (:) for the .not CSS pseudo-class
Merge pull request #28 from leocassarani/patch-12

Fix typo and Markdown link syntax
Merge pull request #29 from leocassarani/patch-13

Use a colon (:) for the :not CSS pseudo-class
tutorial 6
Merge pull request #30 from codebar/advanced-html5

tutorial 6
amend previous commit for now