Not the easiest thing to find, but there is a site for templates and stuff here: kdenlive templates.
There’s not loads on it, and quality may vary. Note that quite a few of these are more like snippets of a project to copy and paste in, so might take a bit of fiddling to get running, compared to just picking “swooshy title #3” and putting your own text in it - but in some form it exists at least :)