This is primarily aimed at making `SourceSpan` and `SourceOffset` usable
in const contexts.
Constifiable functions were found with the
`clippy::missing_const_for_fn` lint, though it reported at least two
false positives.
* Fixed/formatted all intradoc links. Various other small doc fixes/typography/etc.
* Clarified semantic similarity with anyhow/eyre types/macros.
* Removed unused MietteError::SetPrinterFailure.
* README now generaed from lib.rs via `cargo readme`.
* More doc fixes, made ErrorHook type public.
* Indentation (docs).
kleines Filmröllchen
Matthias Beyer
Moritz Mœller
Kat Marchán