Standardized the margin of section headers

[shmowen]

• No discrepancies across browsers (ex: chrome vs safari)
• Accessibility functions
• Pages can scale without distorting page
• No dead links
• Navbar is consistent across the site
• Pages are screen-reader accessible
• Contrast meets standards for accessibility
• Pages are keyboard accessible
• Code is cleaned up and bug-free (ex: debug statements removed)

[shmowen]

Thinking about going back into previous labs to line up their headers as well. Just not sure if it's worth it.