Is there any way to make folders on the "My Repls" page?
No, you can't create folders, however, you can do something that organizes repls in a similar fashion. Click on the three dots all the way to the right of the name of the repl. Click on "edit" and then you can add tags to the repl. You can then filter for repls that have a certain tag attached to them in the search bar by typing "tags:" followed by whatever tag you are looking for. You can make a tag called "awesome" and then search for "tags:awesome" to filter for only those repls. So yeah, there are no folders, but you can organize repls like this. Not sure if you can use spaces in the tags either, since it didn't seem to work for me. Might be a bug.