Compiler Acquisition

[bobbrow]

Many users who are new to C++ install our extension expecting to be able to compile and run programs, but our extension does not bundle a compiler. To help new users onboard quickly we should provide an entry point that will bootstrap this process.

• On Ubuntu, we can issue the `sudo apt install build-essential' command to the vscode Terminal. (need to research equivalent commands for other distros)
• On macOS, we can issue the sudo code-select --install command to the vscode Terminal.
• On Windows, we can provide instructions to install the VS Build Tools. We are not able to run that command automatically. The user needs to validate that they have a valid VS license to install the Build Tools first.

On linux and macOS we can run the respective commands directly from the walkthrough or the Select IntelliSense Configuration drop down item (which should be renamed to "Install a C++ compiler"). On Windows the walkthrough will be updated to show the command to install the VS Build Tools.