Support for execute code plugin (#27)

[soundslikeinfo]

I loaded the project into Claude Code to attempt a fix run-* code blocks. Now the run-* blocks are styled with one known caveat. I don't expect this to be approved, because there remains one issue.

Discovered issue that remains, unable to fold the styled code blocks in live-preview. However, code folding still works in Obsidian's reading mode.

Screenshots

Editing view, Solarized theme

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have checked no similar existing pull requests exist
• I have checked the CONTRIBUTING document
• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly

[soundslikeinfo]

Other issues discovered, like inability to highlight lines of code