Highlight ptrace settings via commented out snippets in certain definitions

[Chuxel]

Revised version of #36

This does not directly add the different ptrace related settings required for Rust, C++, and Go, but includes them as comments in devcontainer.json and docker-compose.yml in several definitions that likely are going to be used as a base to build from.

//cc: @AntonNguyen

[Chuxel]

@chrmarti Made those edits - Thanks! While I was in there, I also raised visibility to appPort and postCreateCommand since I've noticed on vscode-remote-release that people aren't always finding them. They're now both commented out in each devcontainer.json with a note on what they are for to try to help with that problem.

See what you think.

[chrmarti]

@Chuxel Looks good. I wonder if postCreateCommand would benefit from coming with an example. Either on the existing postCreateCommand line or on an additional line above that.

[Chuxel]

@chrmarti That's a good idea - some of the definitions like node would make that easy. Others the command could just print out the version info for the runtime. I'll still leave it commented out but it would anchor the idea. I make that edit.

[chrmarti]

@Chuxel ["uname -a"] won't work. You can use "uname -a" or ["uname", "-a"]. This is similar to CMD, RUN and others in the Dockerfile. The single string will be parsed by a shell and then executed, the array form is executed directly, without a shell.