[x] Allow seeds to reference seeds in other packets based on relative location (normalize nested references on packet planting based on the packet location)
[x] Allow https absolute paths and fetching
[x] Document regex types with describe
[ ] Seed should immediately return Plant() which has a value() that you await. This will be the way to expose intermediate results of sub-seeds.
[ ] Actually support mocked garden.fetchRemoteSeedPacket and test
[ ] A way to fetch all sub-seed referenced locations up front and validate the references before starting a compuation (check for loops in graphs)
[x] Add a test for loading a seed in another packet that was already loaded, and then also one that must be loaded due to that reference
[x] Use new URL() with a file://localhost/foo file for relative
describe
file://localhost/foo
file for relative