We have docs that use an env var `BITCOIN_MSRV` that no longer exists.
Point readers towards `RUSTUP_TOOLCHAIN`.
(Note that we still use `TOOLCHAIN` in the script but it is being phased
out, `RUSTUP_TOOLCHAIN` works today.)
We have stale docs referring to the old MSRV. We do not need MSRV docs
in `CONTRIBUTING` because we have them in the README already.
Fix stale docs by doing:
- Remove the MSRV docs from readme in favour of `CONTRIBUTING.md`.
- Add a sentence to the redame pointing readers towards `CONTRIBUTING.md`.
This warns contributors about possible rebases. Changing CONTRIBUTING
should ensure that GitHub will display special warning. This will be
removed after migration is done.
We currently sometimes have one newline before headings and sometimes
two, its not important which it is but uniformity is nice.
Use two newlines before headings uniformly in `CONTRIBUTING.md`.
Tobin C. Harding
Martin Habovštiak
Dr Maxim Orlovsky