Add author field to meta data

[delphidabbler]

There is no recognised way to specify the author or authors of a snippet. It has been common practice to put an acknowledgment in the Extra field, but this can't be parsed programmatically.

An Author or Authors field could be added to which a name or comma separated list of names would be added.

[delphidabbler]

An Author field could be parsed to generate a contributors list and/or could be used to add missing names to the CONTRIBUTORS file.

[delphidabbler]

A missing Author field should be interpreted as unknown.

[delphidabbler]

At least some acknowledgements in the Extra field state that a person contributed a snippet, not that they authored it.

Maybe a better field name would be Contributor (singular).

But note that the contributor and author could be different people. The Delphi Tips micro-site has fields for both.