Line numbers shouldn't be treated as source code

[ediardo]

Describe the bug
Kmdr code block interprets line numbers from an original code block as source code.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://react-table.tanstack.com/docs/quick-start#define-columns
2. Revert to original code block and see that line numbers aren't part of the source code

Expected behavior
Line numbers shouldn't be treated as source code

Screenshots

Desktop (please complete the following information):

• Version 4.7.12

[ediardo]

Also affects code blocks here https://kentcdodds.com/blog/super-simple-start-to-css-variables