The paraphrase of why a wide index is refused was shorter and said less than
the message; and the keybinding table came from NEXT.md, which is two keys
behind flan-mode.el, so it now reads the keymap instead.
The rule was "capitalised is a type", which leaves i32 and string looking like
ordinary names in the one position — a signature — where the reader is there
to see the types.
The blocks that are not programs were the ones that had drifted: the usage text
had lost its indentation and the refusal table had trimmed "(see plan.org)" off
every message, so the page was showing wording the compiler does not print.
Everything here is checked against the compiler rather than against plan.org:
the design documents describe a language larger than the one that runs, and a
page that documented the plan would mislead the first person to try it.
