feat: support customizing number of the numbered list

[LucasXu0]

No description provided.

[codecov]

Codecov Report

Merging #219 (72a1269) into main (9610ab8) will increase coverage by 0.27%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #219      +/-   ##
==========================================
+ Coverage   62.45%   62.72%   +0.27%     
==========================================
  Files         230      230              
  Lines       10255    10276      +21     
==========================================
+ Hits         6405     6446      +41     
+ Misses       3850     3830      -20     

Impacted Files	Coverage Δ
...mponent/base_component/markdown_format_helper.dart	100.00% <100.00%> (ø)
...ck_component/bulleted_list_character_shortcut.dart	100.00% <100.00%> (ø)
...ng_block_component/heading_character_shortcut.dart	100.00% <100.00%> (ø)
...block_component/numbered_list_block_component.dart	92.06% <100.00%> (+2.40%)	⬆️
...ck_component/numbered_list_character_shortcut.dart	100.00% <100.00%> (ø)
...uote_block_component/quote_character_shortcut.dart	100.00% <100.00%> (ø)
..._block_component/todo_list_character_shortcut.dart	100.00% <100.00%> (ø)

... and 4 files with indirect coverage changes