A bold checkbox label renders incorrectly

[Leonya]

Consider the following markup:

- [ ] a checkbox
- [ ] **a bold checkbox**

The first checkbox is rendered correctly, but the second one isn't, the label is displayed twice: once in bold, once as raw markup.

[Leonya]

Closing since there's been no activity here for a while. This is supported by https://github.com/linsir/markdown-it-task-checkbox, by the way.

[raulsalitrero]

ive tried to fixit in this pull request #29