feat: take allons by version, not by neighbor

Allons is published now, and its v0.0.1 tag points at the exact commit
the local replace directive had pinned. Requiring it like any other
module means a bare checkout of this repository builds anywhere -- no
sibling directory, no worktree, no prior arrangement. The README stops
asking for three repositories side by side and explains the workspace
route for anyone hacking on the framework itself.

commit

3a68143ec0e8c708de55db395ca8d95bf076e418

parent

d77d55823e6d568761ad5a14d139980fad365198

author

Dami <dami.etoile@gmail.com>