[ENHANCEMENT] Show library documentation with a light or dark theme depending on the active color theme

[mardukbp]

Is your enhancement request related to a problem? Please describe.
Currently, the library documentation is shown as black text on a white background regardless of the active color theme. With a dark color theme the contrast between the code and the documentation is unpleasant.

Describe the solution you'd like
If a dark (light) theme is selected the documentation should be shown with a dark (light) theme.

Describe alternatives you've considered
I opened an issue in the RF repo to add a stylesheet parameter to libdoc to be able to specify the stylesheet used when generating the documentation in HTML format.

Additional context

The RF LS extension already offers this functionality:

[d-biehl]

The theme of the documentation is sadly dependent on the OS theme, if you switch the windows color theme to dark mode, you will get a dark documentation and otherwise.

This is handled in the CSS of the library, which I can't change at the moment.
But I'm working on it.

[mardukbp]

Yeah, you are right. I checked the code of the LS extension. They just replace "prefers-color-scheme: dark" based on vscode.window.activeColorTheme.kind. It is a quick way to achieve the desired result, but I think that supporting both the OS-level and the VS Code-level color theme settings in the CSS would provide more flexibility. Here are some implementations that one could consider.

[d-biehl]

Waiting for implemention of robotframework/robotframework#4497