This reverts commit 658e556a4a.
On the second thought, this may be a bad idea because using this crate
on Topola's main library code would pollute it with `egui` code.
The purpose of this new crate is to provide a system for managing
actions that can be bound to a key and to derive `egui` menus to invoke
them.
I haven't moved all relevant code from `topola-egui` (in particular,
`Switch` and `Trigger` structs) to this crate yet.
I ran the following command in Fish shell:
```
reuse annotate --skip-unrecognised --copyright="Topola contributors" --license="MIT" **.{rs,md,toml}
```
The choice of year 2024 in the copyright statements is intentional.