docs: add import-graphTypes.js example file to demonstrate selective graphTypes imports

Added a new example file `import-graphTypes.js` to showcase how to selectively import the `graphTypes` module, highlighting usage of `GraphNoun`, `GraphVerb`, `NounType`, and `VerbType`.

examples/import-graphTypes.js

@@ -0,0 +1,24 @@
+// Example of importing only the graphTypes module
+import { GraphNoun, GraphVerb, NounType, VerbType } from '@soulcraft/brainy/types/graphTypes';
+
+// This demonstrates that we can import just the graphTypes
+// without importing the rest of the library
+console.log('Successfully imported graphTypes');
+
+// Example usage of the imported types
+const exampleNoun = {
+  id: '123',
+  createdBy: {
+    augmentation: 'test',
+    version: '1.0',
+    model: 'test-model',
+    modelVersion: '1.0'
+  },
+  noun: NounType.Person,
+  createdAt: { seconds: Date.now() / 1000, nanoseconds: 0 },
+  updatedAt: { seconds: Date.now() / 1000, nanoseconds: 0 }
+};
+
+console.log('Example noun type:', exampleNoun.noun);
+console.log('Available noun types:', Object.values(NounType));
+console.log('Available verb types:', Object.values(VerbType));