[FEATURE REQUEST] Allow User Script to be in Note code block

[l-mb]

Is your feature request related to a problem? Please describe.

Currently, a user script for a macro choice lives in a .js file that Obsidian can't natively edit or even display.

Especially on mobile, this is somewhat suboptimal UX.

Describe the solution you'd like

Allow specifying a note (e.g., script.md rather than script.js), extract the single ```js block, and use that as the script.

Ignoring everything before or after the block would allow for added comments and notes.