Colorful

Add syntax-highlighting with the help of Prism

Cleanup

• Cleanup Admin Notices (remove deprecated classes)
• Cleanup Alternative Colors

Happy New Year

• Fix: Code sample should not be escaped.
• Fix: Small grammatical correction.
• Add: Add installation instructions.

WP 4.4 Ready

Headings hierarchy changes in the admin screens. ( see #33 )
Update Dashicon Picker for all Dashicons, new one since WP 4.3. ( see #31 )