Regrets, I was about an hour ago but was called away without chance to log off. In the event you are caching zzzz's, I will outline some stuff you can work on or answer.
OK, so Fedora default GNOME edition, and it has an app Files aka Nautilus which you don't like, or at least prefer Cinnamon's Nemo which you have installed and wish to use as default FM (file manager), and have it show in your Launch Dock (dock) which by default is at left, or could be top or bottom if you have tweaked the Settings - Appearance options.
And you are asking for it to be in your List of Applications
True? If different, tell me how so.
I'll proceed ahead on the basis of what I have conjured/conjectured.
List of Applications or Applications List, under GNOME, is the name given to the desktop icon showing as
Nemo should already be in there, albeit it may have a name a little different eg File Manager, or something other to distinguish it from Nautilus. If you can't find that, or be sure, go to Terminal and enter
and see what the result is.
If it is there, then all you need to do is to replace the icon for Nautilus on your Dock, and substitute Nemo.
From the Dock, you can right-click on Nautilus and choose Remove from Favourites, and it will vanish.
Then from your Applications List, once you have identified the icon and name for Nemo, you can right-click it there and choose Add to Favourites, it will then appear on your dock, and is now effectively your default FM.
Do not delete, or in any way other than that described, remove Nautilus from your GNOME Linux distribution!
Each of the DEs and their associated FMs are intimately and intricately dependent on each other. If you remove the FM, you will break the desktop. It is simpler to just shuffle the one getting replaced to be out of sight.
I do prefer Nemo since I used Mint Cinnamon for quite some time, so that is most familiar to me. I can consider going to Cinnamon on Fedora but I do like using the Gnome DE since I also used Pop OS for a while. I think I would prefer to stick with Gnome and get Nemo set to default/show in applications menu, but if necessary I can try Cinnamon again.