Autocomplete hie.yaml

**Is your feature request related to a problem? Please describe.**

I dont write hie.yaml every often, that make me have to open the hie-bios readme to find how to write a valid hie.yaml.

So I'm thinking if possible to support autocomplete for hie.yaml, no context, just keywords completion.

**Describe the solution you'd like**

**Describe alternatives you've considered**

**Additional context**