This template is an empty project containing the Monogame Framework. You can open the project in JetBrains Rider and have a functioning game almost instantly.
You can download the entire repository as a zip file and extract it, or clone it using:
https://github.com/Limeoats/Monogame-Rider-Template.git
To set up this template, you need to go through the project and rename the files where you see "MonogameRiderTemplate" to your project name. Also, with a text editor, edit MonogameRiderTemplate.sln, MonogameRiderTemplate.csproj, and AssemblyInfo.cs, changing the words MonogameRiderTemplate to your project name.
Once done, open the .sln file in Rider and try to compile.
If you have any questions, feel free to head over to https://limeoats.com/forum and post them there.