Use logical chapter names

[jimbaker]

Use naming like 01-language-and-syntax.rst instead of chapter1.rst. Lexicographical ordering is preserved (currently it is lost due to chapter1 vs chapter10), while allowing people to more readily find a specific chapter to edit.

[jeff5]

... although even the 01 is a hostage to fortune. If you delete/merge/reorder chapters there's a lot to change. I guess this is why ../_images/chapter19-eightqueens.png is an illustration in Chapter 18. If someone has the enthusiasm to rename everything, lets not use numbers.

[jeff5]

Using the (almost!) logical chapter names from Josh Juneau's (@juneau001) repository (see #14) seems to work, provided one pays attention to the re-ordering of chapters. I think I will not push until that is satisfactory too.

Aligning the content is another step, as would be organising the images on the same principle.