educe.util: Fix formatting on API docs
Code formatting tweak

We can use brackets in imports (and ifs to avoid backslash
explosion)
stac-util: more sophisticated module help

Now allow the module to say longer things in the epilog,
always as part of the doc string

Second line and up is the epilog
Code style: group subcommands into sections
Replace stac-util move help boilertext with actual help
educe.util.add_subcommand: for swiss-army knife utilities

Add a module to a subparser set following some conventions
for how module name and help text translate to help strings
Refactor subcommand management in helper scripts
stac-oneoff (split from stac-util)

Tools that we don't expect to get much regular use.
Note that we lose stac-util weave along the way;
it was a rather short lived utility
educe.stac.util.unannotated_key
doc section for stac one-off
educe.stac.util.csv name CSV_HEADERS constant
educe.stac.util.csv.Turn

Corresponds to a row of our internal csv files