navigation vim: lock fn layer

[bouttier]

The documentation said the Fn layer should be locked : https://github.com/OneDeadKey/arsenik/blob/d433298231b9c6ca4ea7bacf41c2b3dbc23a14f1/README.md?plain=1#L147-L148 This PR fix the config to match the doc.

But I prefer than this PR #50!

[fnuttens]

Good catch, however I believe the funpad works better as a layer-while-held. Most of the time, I just want to hit a single Fn key; having to manually leave the layer would feel a bit cumbersome. It’s not like the numpad where you’re often staying for more than 2 keys. Maybe we should change the README instead?

Edit: I just went through https://github.com/OneDeadKey/arsenik/pull/50 and like this proposal much better 🙂