Introduce file header documentation

[davidkopp]

Closes #10.

We have to add a file header to every file. You can use the VS Code extention psioniq File Header to automatically add a header to every new file and to update the headers of files you edit. The template is placed in the workspace settings: .vscode/settings.json.

To set the author information you can add the following to your user settings (change author, initials and authorEmail):

"psi-header.config": {
    "forceToTop": true,
    "blankLinesAfter": 1,
    "author": "David Kopp",
    "initials": "DK",
    "authorEmail": "mail@davidkopp.de",
    "creationDateZero": "blank"
}