Improve styling of repl blocks in pydoc's HTML output #160998

Many docstrings contain repl-based examples, for example turtle. In the documentation, it renders as a code block, like so:

However, in pydoc the example does not have any special styling, and as such renders like plain text:

I propose to add a little styling, so it is rendered like a distinct code block, for example:

Adding colour is a possible follow-up.

Linked PRs

• gh-160998: Render interactive examples as code blocks in pydoc HTML output #160999