feat: enable experimental log batching through config

adding `experimental_log_batching_enabled = true` to the config file
enables this feature

feat: add status bar to diff view

feat(rebase): add insert between mode

Pressing `i` will switch to insert between mode by setting the currently
selected revision to be the `--insert-after` argument, and the revision
where the `enter` is pressed will be the `--insert-before` argument.
Effectively running; 

`jj rebase <your source> --insert-after <where i was pressed> --insert-before <where enter was pressed>

idursun#66

chore(nix): Add flake check GH action.

Just to make sure that jjui is buildable with nix.

Previusly, if we added a new Go dependency, we
wont notice since CI was not testing with nix.
Now for every commit, we make sure that the
package builds correctly under nix.

feat(details): show `*` binding in the status

feat(help): add new key bindings to help

feat(oplog): make op log limit configurable defaulting to 100

ci: update go toolchain version

feat(undo): show last operation in confirmation

ci: update release workflow