Allow configuration of default script language

[devmattrick]

Is your feature request related to a problem? Please describe.
Right now, when auto-importing a component, it just defaults to adding a "vanilla" JS script tag. I do all of my work in Svelte in TypeScript so I need to go back and add a lang="ts" to the script tag.

Describe the solution you'd like
It'd be awesome if there was a way to configure the default script language in the plugin's configuration. This would simply just add lang="<lang>" to the generated script tag when a component is imported. This could in theory be extended to other cases where script and even style tags are generated.

Describe alternatives you've considered
Could always just do it the way I'm doing now but this would definitely be a small productivity boost.

Additional context
I'd be willing to help out with this one if this is a change that you like 😄

[jasonlyu123]

I think It would a nice addition. If you like to work on this. Follow the instruction in the README to set up the dev environment. You can find the config list in ls-config, package.json for svelte-vscode, and the README for language-server. The script tag generation is in the CompletionProvider.