Monorepo per project replacements

[miniscruff]

Is your feature request related to a problem? Please describe.
If you are using a monorepo configuration there is currently no way of adding per project replacement options. In fact, I am not sure we should allow the global replacements as an option if projects are enabled.

I am also curious to know if teams might consider per project headers and footers, right now the global header and footer would be used, if defined, for each project release. It sort of feels like, to me anyway, that under the project config you could include any of the global configs and when doing so you disable the global value in favor of the project one.

Describe the solution you'd like
Replacement option per project

Describe alternatives you've considered
I don't think there is one.

Additional context
We may want to consider other global level configs as per project configs, before moving projects/monorepos from preview to stable.