Add type definitions for Vue build output

[AaronDewes]

This makes it easier to use Bitcoin Icons from Vue + TypeScript projects

[GBKS]

This is where I'm showing my lack of knowledge of this stuff, but what does this practically do...?

[AaronDewes]

This is where I'm showing my lack of knowledge of this stuff, but what does this practically do...?

When using TypeScript with Vue without this change, trying to import the icons leads to an error. That error only happens in development environments and does not actually affect anything, but is annoying.

[GBKS]

Thanks. Will this require re-publishing the Vue module?

[AaronDewes]

Yes, but it can also simply be included in the next release