To use $
and other “special” markers, you must first enable expand Other options and tick Regular expressions check box.
Enter $
in Find and ensure Replace contains a single space.
Press Find Next
to find the next end of paragraph. Press Replace
only if you think this is not a real paragraph end by a mere line wrap.
Keep the paragraph markers where they denote true end of paragraphs.
To show the community your question has been answered, click the ✓ next to the correct answer, and “upvote” by clicking on the ^ arrow of any helpful answers. These are the mechanisms for communicating the quality of the Q&A on this site. Thanks!
In case you need clarification, edit your question (not an answer which is reserved for solutions) or comment the relevant answer.