Fixing up internal links

[pronoiac]

We (finally) have a way to make links between chapters that work on Github and in the ebook - see PR #195.

To catalog all the types of links pointing within the book, and organize / track the work:

• footnotes - #fn01-1 and #tfn01-1 - around 55 anchor and link combos, already handled
• section of a chapter - #section_1.7 - WIP branch, around 60 links, 300 anchors
• page number - #p853 - around 55 links, 1k anchors
• bibliography entries - bibliography.md#bb1160, around 140 links, 330 anchors
  • currently, e.g. [Steele (1990)](bibliography.md#bb1160)
    could fix links by editing bibliography.md
  • could aim at, e.g. [Steele (1990)](bibliography.md#steele-1990)
• figures - could clean up, around 40 links
  • [figure 11.1](#f0010)
  • [figure 16.2](#fig-16-02)
  • [figure 23.3](#figure-23-3)
• exercise - [exercise 8.8](#st0045) - only one link?

Going to an anchor midway down a page could take some fiddling in some browsers, due to how Github renders Markdown pages.