Changing variable width name
Change name of divineProportion to content
Change name of proportion to divineProportion
Change prompt and alert (Divine Proportion to The Content of your layout)
Fix caps in introduction
Explaining what the variables are
Explaining prompt
Explaining formula for Content
Explaining how to find the Side Bar measure
Correct word in Content definition: layout instead of block
Explaining Content layout alert
Explaining side bar alert
New header