plugin initializer should add `firebase-tools` as a dev dependency

[simondotm]

this allows CI systems to npx firebase ... Necessary for github actions that dont use the firebase action

[ciriousjoker]

This is actually pretty useful, because of issues like this:

• https://github.com/firebase/firebase-tools/issues/4952

[simondotm]

as of 0.13.0-beta.0 this is now supported.