🚀 RELEASE: v2.1.0

[chrisjsewell]

@hukkin do you have any objections, regarding releasing this as 2.1 rather than 3.0?
Fo 99% of use cases, I don't think there should be a noticeable change, moving from attrs to dataclasses (it certainly did not affect myst-parser)

[codecov]

Codecov Report

Merging #213 (1393760) into master (145a484) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #213   +/-   ##
=======================================
  Coverage   96.08%   96.08%           
=======================================
  Files          62       62           
  Lines        3221     3221           
=======================================
  Hits         3095     3095           
  Misses        126      126           

Flag	Coverage Δ
pytests	96.08% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
markdown_it/__init__.py	100.00% <100.00%> (ø)

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[hukkin]

I don't object either version.

Personally I'd do 3.0 mainly because of Remove deprecated NestedTokens and nest_tokens. The deprecation is a nice warning, but if we strictly follow SemVer, I don't think it makes the removals any less breaking.

[hukkin]

If you plan to merge #214 it may be a good idea to do so before the release. Merging it afterwards will introduce a breaking change, as __slots__ objects are stricter than objects without it (can't assign attributes dynamically).