Rename container to be more generic

[drewroengoogle]

• Change the container/image to have a more generic name, as we can use it in other places besides website staging
• Update the readme to reflect this change
• Change the directory

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[khanhnwin]

I don't have approval permissions for this repo. Halp @parlough? Thank you!

[parlough]

I don't have the full context, but looks good to me :)

[drewroengoogle]

I don't have the full context, but looks good to me :)

The context is that we realized we are currently building two separate containers that both are used for deploying to firebase, and this one is able to cover both of those cases, meaning we don't have to make updates in two places if we want a new version of firebase-tools. I just wanted to change the naming for clarity

[parlough]

Less duplication sounds great to me!

Maybe you have already, but you should also check in with Dart EngProd as they might want/need to migrate the Dart specification deployment as well :)

[khanhnwin]

@parlough Yep! That's on our list. Michael's flagged us down for that :)