Add .svelte file type to default type list

[josbra-attensi]

Describe your feature request

Svelte is popular enough with it's own file types .svelte and .svelte.ts (the latter would still be picked up by searching -tts but would probably make sense to add to the .svelte glob.

I would like to be able to simply run rg "my query" -tsvelte and not add the --type-add flag each time. I think this makes sense because it is now an established file type, and not my own made up filetype.

Maybe add to the existing list:

svelte: *.svelte, *.svelte.ts

or similar? :)