feat: add wutta top-level command with make-uuid subcommand

i think it only makes sense to have an "opinion" for command line
interface in this project, and we probably need more `wutta`
subcommands too but we'll see.

main motivation for this currently is to allow poser apps to define
their own CLI, in particular e.g. `poser install`

docs/narr/cli/custom.rst

@@ -0,0 +1,105 @@
+
+Custom Commands
+===============
+
+WuttJamaican comes with :doc:`/narr/cli/builtin`.
+
+Using the same framework, each :term:`package` can define additional
+top-level :term:`command(s)<command>` and
+:term:`subcommands<subcommand>` as needed.
+
+
+Top-Level Command
+-----------------
+
+You must "define" *and* "register" your top-level command.  Assuming a
+basic Poser example:
+
+.. code-block:: none
+
+   poser-project
+   ├── poser
+   │   ├── __init__.py
+   │   └── cli.py
+   └── pyproject.toml
+
+Add the command definition to the ``poser.cli`` module::
+
+   from wuttjamaican.cli import make_typer
+
+   poser_typer = make_typer(
+       name='poser',
+       help="Poser - the killer app"
+   )
+
+Then register the command as script in ``pyproject.toml``:
+
+.. code-block:: toml
+
+   [project.scripts]
+   poser = "poser.cli:poser_typer"
+
+Then reinstall your project:
+
+.. code-block:: sh
+
+   pip install -e ~/src/poser
+
+And now you can run your command:
+
+.. code-block:: sh
+
+   poser --help
+
+But it won't really do anything until you add subcommands.
+
+
+Subcommands
+-----------
+
+You must "define" the subcommand of course, but do not need to
+"register" it.  (That happens via function decorator; see below.)
+
+However you *do* need to ensure all modules containing subcommands are
+"eagerly imported" so the runtime discovery process finds everything.
+
+Here we'll define the ``poser hello`` subcommand, by adding it to our
+``poser.cli`` module (from example above)::
+
+   import sys
+   import typer
+   from wuttjamaican.cli import make_typer
+
+   # top-level command
+   poser_typer = make_typer(
+       name='poser',
+       help="Poser - the killer app"
+   )
+
+   # nb. function decorator will auto-register the subcommand
+   @poser_typer.command()
+   def hello(
+           ctx: typer.Context,
+   ):
+       """
+       Hello world example
+       """
+       config = ctx.parent.wutta_config
+       app = config.get_app()
+
+       name = config.get('hello.name', default="WhoAreYou")
+       sys.stdout.write(f'hello {name}\n')
+
+       title = app.get_title()
+       sys.stdout.write(f'from {title}\n')
+
+   # TODO: you may need to import other modules here, if they contain
+   # subcommands and would not be automatically imported otherwise.
+   # nb. *this* current module *is* automatically imported, only
+   # because of the top-level command registration in pyproject.toml
+
+No need to re-install, you can now use the subcommand:
+
+.. code-block:: sh
+
+   poser hello --help