rhai fmt should honor tabsize

[schungx]

The formatter should honor the default Rhai tab-size:

"[rhai]": {
    "editor.tabSize": 4
}

unless explicitly overwritten, I suppose.

Right now it auto-formats to 2 spaces.

[tamasfe]

Weird, if you change the tabs for a file, it does. I guess we'll have to manually read this config in the language server.

[schungx]

That's correct. I can manually change the tab setting for an individual file and rhai fmt will honor it. However, if I don't do that, it somehow defaults to 2 spaces.