Prepare for v0.8

[CathalMullan]

• rustdoc refresh (public only, we can document private post release)
• clean up clippy allows
• errors refresh
• Separate crate documentation from README
• Document escaping, why we don't use '{{'
• Should explain routing priority logic better.
• Might kill the EncodingError enum, since it's just a reimplementation of UTF8Error currently.
• Can probably collapse a lot of the files too, no need for so many.
• Insert conflict error needs better handling, actual error message.
• Update local benchmark result
• Changelog (post-merge)
  • Should mention why we dropped the decoding support too I suppose.
• run a spellchecker (grab one from Nix)?

[codecov]

Codecov Report

Attention: Patch coverage is 81.13553% with 103 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/constraints.rs	11.76%	30 Missing ⚠️
src/node/search.rs	43.33%	14 Missing and 3 partials ⚠️
src/node/display.rs	76.27%	2 Missing and 12 partials ⚠️
src/parser.rs	77.77%	10 Missing and 4 partials ⚠️
src/lib.rs	56.00%	9 Missing and 2 partials ⚠️
src/node/insert.rs	86.36%	9 Missing ⚠️
src/router.rs	94.11%	3 Missing ⚠️
src/node/find.rs	71.42%	2 Missing ⚠️
src/state.rs	0.00%	2 Missing ⚠️
src/node/optimize.rs	85.71%	0 Missing and 1 partial ⚠️

Files with missing lines	Coverage Δ
src/errors/constraint.rs	100.00% <100.00%> (ø)
src/errors/delete.rs	94.44% <100.00%> (+1.58%)	⬆️
src/errors/insert.rs	98.90% <100.00%> (+5.35%)	⬆️
src/errors/template.rs	100.00% <100.00%> (+1.09%)	⬆️
src/node.rs	100.00% <100.00%> (ø)
src/node/delete.rs	41.35% <ø> (ø)
src/nodes.rs	91.83% <100.00%> (ø)
src/node/optimize.rs	74.65% <85.71%> (ø)
src/node/find.rs	67.54% <71.42%> (ø)
src/state.rs	53.84% <0.00%> (-6.87%)	⬇️
... and 7 more

[codspeed-hq]

CodSpeed Performance Report

Merging #231 will degrade performances by 4.6%

_{Comparing 230-prepare-for-v08-release (fa4b105) with main (12308ad)}

Summary

❌ 1 regressions
✅ 15 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	230-prepare-for-v08-release	Change
❌	matchit benchmarks/routefinder	47.9 µs	50.2 µs	-4.6%