S-K to switch to popup window to navigate contents

Some popup windows contain more content than their size, requiring scrolling to see all the text.

Update relevant sections of the book to show how to move the cursor to those popups so the text can be scrolled through.

## References

https://discord.com/channels/939594913560031363/1311079962144411658/1311079962144411658

Try on doc and lsp popups