Appcli

Feature
* Log the attribute lookup process ([`de22e5a`](https://github.com/kalekundert/appcli/commit/de22e5abc01cfa5bd55018e65eaefcc9536cf85a))

Fix
* Use 'is' when comparing values to *ignore*. ([`41acd1d`](https://github.com/kalekundert/appcli/commit/41acd1dc78fe72b6f05d28af1be07d5ed8a27e5d))

Fix
* Allow falsy config keys ([`bd66fba`](https://github.com/kalekundert/appcli/commit/bd66fbada4e78386ced3b5cb42c37beeea3590fa))

Feature
* Try rtoml before falling back on toml ([`accf065`](https://github.com/kalekundert/appcli/commit/accf065efb60111e903e142fe645d3fdb1485cd7))

Fix
* Add config_cls argument to app.load() ([`55ebe2a`](https://github.com/kalekundert/appcli/commit/55ebe2aeb3d8ed9b9db8a0868f2648d44ea54bae))

Fix
* Don't share bound getters between instances ([`2d72a0e`](https://github.com/kalekundert/appcli/commit/2d72a0e6d8a2b198c8439b834ea4749ea517601b))

Documentation
* Organize README into sections ([`d674072`](https://github.com/kalekundert/appcli/commit/d6740725450c541b8102f104ee849d6be1feffce))
* Link to examples from stepwise_mol_bio ([`d45b44a`](https://github.com/kalekundert/appcli/commit/d45b44a8705036f5d2638d54c6d99afc9def2adf))

Fix
* Make layers mutable again ([`7b23c01`](https://github.com/kalekundert/appcli/commit/7b23c010b713182a258b8d98fc3475175ec19979))

Documentation
* Fix doctest ([`6e0c25b`](https://github.com/kalekundert/appcli/commit/6e0c25b8d6f187325461c346f8194a74ed3c9698))