Add support for multiple crate installation

[pronebird]

Hi

Is it possible to provide support for specifying multiple crates for installation? for ex:

- name: Install cargo-get
   uses: baptiste0928/cargo-install@v3
   with:
     crate: cargo-get
- name: Install cargo-edit
   uses: baptiste0928/cargo-install@v3
   with:
     crate: cargo-edit

It would be shorter to do this:

- name: Install cargo bins
   uses: baptiste0928/cargo-install@v3
   with:
     crates:
        - crate: cargo-get
        - crate: cargo-edit

[baptiste0928]

Hi! This could be a nice quality of life improvement, it's not the first time someone suggests it.

I don't have much time to work on new features right now, but if you or anyone else want to give it a try, I'll be happy to review the PR.