copy typescript type definition file to the dist folder after build

[gynekolog]

Why am I submitting this PR

This resolves missing typescript definition file in the production build.

Does it fix an existing ticket?

Yes #694

[gynekolog]

The quickest way is to copy the index.d.ts file to the dist folder.

It will be better generate types from the source files. I tried that with the command

npx -p typescript tsc src/**/*.js --declaration --allowJs --emitDeclarationOnly --outDir dist

but the process failed because the vue types are missing.
I could try it later but for now, copying the file currently fixes the issue.

[gynekolog]

Hello @karellm, is there any action what can I do to have the pull request merged?

[karellm]

Thanks. This is in 7.5.0