Add inlay hints

[azdavis]

Problem

You can hover over things to get their type, but there's no way for Millet to "always" show this information without hovering.

Solution

Add support for inlay hints, which could show this information. It's in the LSP standard.

[azdavis]

Already somewhat implemented

https://github.com/azdavis/millet/blob/4e0bed39cdb0e858cbbf84248537bdd3a01dabcc/crates/analysis/src/lib.rs/#L280-L308

[azdavis]

Done in v0.12.0

[bzy-debug]

Is there an option to turn off the inlay hint?

Inlay hint sometimes makes the function less readable:

It breaks the indentation of function implementation

[azdavis]

you can turn them off via editor.inlayHints.enabled in vscode

[azdavis]

https://github.com/azdavis/millet/blob/main/docs/manual.md#inlay-hints