Fix Rigimesh typo, should be Rigi-mesh (or Rigi-Mesh)

Written as Rigi-mesh here and in the index, but Rigi-Mesh elsewhere.
Add missing anchor for page 275
Use small-caps for the <H3> captions, like the book
Format footnotes as [1] for clickability
Fix typo in appendix A
Dashify appendix A
Fix typo in appendix B
Dashify appendix B
Fix typos in appendix C