How can I add another importable root-level directory to my NX workspace

Question

I would like to add another directory like libs in the root of my project form which apps can import. In my case, I have a set of microservices in a functions directory and I would like one of my apps to import the interfaces directly from this directory rather than create yet another lib just to hold the sharable interfaces.

(Trust me, I've thought this decision through)

how can I modify my boundary rules to permit imports for this directory?

    "@nrwl/nx/enforce-module-boundaries": [
      "error",
      {
        "enforceBuildableLibDependency": true,
        "allow": [],
        "depConstraints": [
          {
            "sourceTag": "*",
            "onlyDependOnLibsWithTags": ["*"]
          }
        ]
      }