docs: make DPS STAC guide visible

[hrodmn]

Add the DPS STAC metadata guide to the Technical Tutorials navigation.

resolves #597

[wildintellect]

Should we update some of the text before we list it? Maybe that's a minor for later thing.

• Link in description are broken (translating to relative urls)
• Why to catalog description is a bit inverted.
• needs to be more clear that more than COGs can be cataloged

Side Ticket:

• Make sure STAC browser works with DPS catalog and include how to browse items once added

cc: @sujen1412

[wildintellect]

I mentioned to @sujen1412 that the only blocker I have on this, now is that we should tag the DPS STAC as Beta or Experimental with a statement that migration of records to future changes will be possible but might not be automatic. However the effort to use is low and the benefits can be great.

@sujen1412 also asked a question, what about cataloging existing items (e.g. files imported to MAAP), and I mentioned the example algorithm is actually a catalog only operation on existing files.