Added cli doc generation and refactored examples

[zr-msft]

…Examples field

Here is a launch.json for testing:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Generate Docs",
            "type": "go",
            "request": "launch",
            "mode": "auto",
            "program": "${fileDirname}",
            "env": 
                {
                    "GEN_CLI_DOCS": "true"
                },
        }
    ]
}

MD files are generated in notation-reference-doc but have been added to .gitignore to avoid adding them to the repo

If environment variable is absent, behavior should be normal.