0.2.8: Lax Optics

Previously, implementing an Optic for lax open hypergraphs was very annoying. You'd have to:

• Translate your term to strict
• Define a Fwd functor
• Define a Rev functor
• Define the Optic with the data-parallel interface
• Map your strict term and then optionally adapt it
• Translate back to lax

Now things are easier:

• Define a struct like MyOptic, and implement the lax::Optic trait
• Call map_arrow or map_adapted