🔧 Improve typing for `MarkdownIt.add_render_rule`

[chrisjsewell]

Make the function signtature more explicit

[codecov[bot]]

Codecov Report

Patch coverage: 91.66% and project coverage change: -0.03 :warning:

Comparison is base (bee6d19) 95.17% compared to head (a43a87b) 95.14%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #287      +/-   ##
==========================================
- Coverage   95.17%   95.14%   -0.03%     
==========================================
  Files          64       64              
  Lines        3437     3443       +6     
==========================================
+ Hits         3271     3276       +5     
- Misses        166      167       +1     

Flag	Coverage Δ
pytests	95.14% <91.66%> (-0.03%)	:arrow_down:

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

Impacted Files	Coverage Δ
markdown_it/main.py	87.07% <50.00%> (ø)
markdown_it/renderer.py	98.27% <80.00%> (-0.84%)	:arrow_down:
markdown_it/parser_block.py	91.83% <100.00%> (ø)
markdown_it/parser_core.py	100.00% <100.00%> (ø)
markdown_it/parser_inline.py	95.52% <100.00%> (ø)
markdown_it/ruler.py	87.78% <100.00%> (+0.18%)	:arrow_up:
markdown_it/rules_block/state_block.py	86.95% <100.00%> (ø)
markdown_it/rules_inline/state_inline.py	97.72% <100.00%> (+0.02%)	:arrow_up:

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.