Expand Data Privacy page to include web site

[tfmorris]

The Data Privacy seems to focus entirely on the OpenRefine tool, but typically these also include things like web server log retention info, etc. It should probably be expanded to include at least cursory info or pointers to data privacy statements for:

• openrefine.org web server
• mailing lists
• Discourse (if we end up going that direction)
• Gitter

Even just a list of these things and statement that they have their own privacy statements would be a starting point.

[wetneb]

I just realized that it would probably make more sense to integrate the current privacy page into the documentation, since this is really about the tool itself. The current page ought to be, indeed, about the website itself (and we can hopefully keep it short given that it is just a static website).