Add a glossary of common terms

[adam2k]

Resolves #50

Add a glossary of common terms after the appendix.

[willcl-ark]

Hey Adam, this looks like a great start to this section!

I added a second commit with some minor fixups which I noticed on a first read. Perhaps you could check if you are happy with them?

I pushed a version with these two commits to https://obc.256k1.dev/#_glossary already, so you can see what it looks like live (which you can also do locally by running asciidoctor -r asciidoctor-diagram --verbose --trace index.adoc; open index.html FYI).

Edit: I know the diff looks large, but really most of it was just newlines (one sentence per line).

[willcl-ark]

Just fixed (my own) tab indentations :)

[adam2k]

@willcl-ark the changes look good! I was able to see them in the git diff, but I didn't see them on the website. Maybe something is still cached for me or you reverted those changes? I tried in two different browsers and I couldn't see the glossary.

[willcl-ark]

Try refreshing the browser cache (ctrl + shift + r or perhaps cmd+shift+r?)

[willcl-ark]

Merged in e9538fc