Set up continuous integration for verifying successful compilation

[kbuffardi]

We want to create a CI workflow called compile so that it builds the application in an Ubuntu environment with the command:
g++ -std=c++17 main.cpp

It should be triggered to run whenever:

• a pull request has been made for the main branch
• any new commits have been pushed to a branch called devops

We also want to integrate a status badge of the compile workflow into README.md so we can quickly see the latest result.