Fixing issues filed by Colin

[arechnitzer]

Fixing issues filed by @cbm755

Needs

• [x] Remove me, md, p from footnotes - since causes html formatting problems. Fixes #12 and fixes #13
• [x] Fix #14 - divergent series are useful
• [x] @joelfeldman makes any relevant tweaks to divergent footnote.
• [x] fix #16 - I think this is the same footnote issue.
• [x] fix #17 - same footnote issue
• [x] fix #18 - tweak it to avoid 0
• [x] fix #19 - embiggen the x. made x small throughout the example.
• [x] @joelfeldman approves the shrinking of X to x... and fixing things with a small t

[arechnitzer]

@joelfeldman I've made the changes in this branch - please take a look and let me know what you think. Also see the commentary on the divergent series footnote tweakery.