In-Kind Donations List

On the Donations page, we should have a list of companies who have provided in-kind donations, and basic information about what they have been.

Examples:

* Obsidian Systems created the HF website
* MLabs donated 40 hrs/mo of development time for a while.
* Scrive is donating 40 hrs/mo starting soon.

I do not want this amazing generosity to fall through the cracks.

Implementation should be a set of markdown in a directory such as `donations/inkind`, with metadata about the company, their URL, the commitment, etc. The free markdown text could eventually be used as a page that goes into the details of the work done, which the company can submit PRs to update.