Add reference to 5min version of system 7333 data

[williamhobbs]

Now that there's a 5min version of system 7333 data from the Solar Data Bounty Prize (system 7334?), it would be helpful to mention that here:

documentation/pvdaq.md

Line 27 in 726265c

* **7333** - A 257 MW Single-axis tracker facility in California. This dataset is at a very high time resolution of 10s for all channels.

[cdeline]

Thanks @williamhobbs, we can add that reference to the 5-minute data on 7334. This is probably also a good time to add description of the PVOutput and PVDB datasets that were recently uploaded to PVDAQ. I'll work up a PR.

[williamhobbs]

@cdeline would this be a good place to mention geojsons if/when they are available?