This solution is based on existing MS shell scripts that launch VS or VSCode.
One can either run a script located at root directory, included here as an example, passing paths to projects/solutions to be opened by Rider:
startrider.sh ./MyApp.sln
The script can be invoked from other locations within your project, to prepeare Rider to open your current project properly setup:
#!/usr/bin/env bash
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
repo_root="$DIR/../.."
"$repo_root/startrider.sh" $DIR