add comment about App.css

[iamef]

Summary 🎯

Bug in official app when I inspect element and check the console
GET https://www.remnoteplugins.com/incremental-everything/0.0.19/App.css net::ERR_ABORTED 403 (Forbidden)

Bug in my test app when I inspect element and check the console
Refused to apply style from 'http://localhost:8080/App.css' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.

Changes 🔁

[iamef]

Probably this is what's happening

Ah, now we know what happened! The issue was that CSS comments in an otherwise empty file were triggering this behavior. This is an interesting edge case.
Two things were likely happening:

The empty file with just a comment wasn't being processed correctly through the webpack pipeline
The webpack dev server was falling back to serving an HTML error page (hence the text/html MIME type) because it didn't recognize the file as valid CSS

This is similar to how some parsers and minifiers might strip comments and then, finding no actual CSS rules, treat the file as invalid or empty.
Now that you've added an actual CSS rule, webpack recognizes it as valid CSS and processes it correctly. If you need to keep an empty CSS file as a placeholder, it's better to either:

Leave it completely empty (no comments)
Or include at least one valid CSS rule, even if it's not used

-Claude.ai