feat: allow dot as separator in resource id (#105)

Signed-off-by: Ben Meier <ben.meier@humanitec.com>

samples/score-full.yaml

@@ -70,6 +70,6 @@ resources:
         data: here
   resource-two2:
     type: Resource-Two
-  resource-three:
+  resource.three:
     type: Type-Three
     id: shared-type-three

score-v1b1.json

@@ -144,11 +144,11 @@
           "pattern": "^[A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9]$"
         },
         "id": {
-          "description": "An optional external Resource identifier. When two resources share the same type, class, and id, they are considered the same resource when used across related Workloads. The id must be a valid RFC1123 Label Name of up to 63 characters, including a-z, 0-9, '-' but may not start or end with '-'.",
+          "description": "An optional Resource identifier. The id may be up to 63 characters, including one or more labels of a-z, 0-9, '-' not starting or ending with '-' separated by '.'. When two resources share the same type, class, and id, they are considered the same resource when used across related Workloads.",
           "type": "string",
           "minLength": 2,
           "maxLength": 63,
-          "pattern": "^[a-z0-9][a-z0-9-]{0,61}[a-z0-9]$"
+          "pattern": "^[a-z0-9]+(?:-+[a-z0-9]+)*(?:\\.[a-z0-9]+(?:-+[a-z0-9]+)*)*$"
         },
         "metadata": {
           "description": "The metadata for the Resource.",