Fix broken DO and ?DO loop counter logic
V2.2: Introduce TCONSTANT support
V2.1: Support for immediate-mode words
Support immediate words and discrete bytes for labels

Problems would occur when you tried to compile words like ." or S", which
resulted in assembly listings containing malformed .byte directives (.byte
Backticks expands < for me
Update appendix A
Updated commentary in rv64.fs
Release 2.0

An accumulation of tweaks made while using Shoehorn to write a new Forth
environment from scratch.
Add DO, ?DO, LOOP, and +LOOP
Add SEAL feature to finalize a dictionary.
Introduce basic header generation.

Doesn't yet support multiple vocabularies, but it can potentially be
easy to do by swapping the contents of vocab out.
Add \-comments and [CHAR] for colon defs.
Inline strings (S") and TX{CREATE,VARIABLE}
Support CREATE, comma
Appendices demonstrating back-ends
Forgot "further work".
First code!!

This version compiled software which ran under k1emu for the first time.
Some changes to its ABI had to be made for this to happen, but on the
whole, the project was a resounding success!!
Use ca65 syntax to enforce locality of labels