docs: add deprecation warnings for addNoun and addVerb methods

- Add @deprecated JSDoc tags to TypeScript definitions
- Update all documentation examples to use modern add() and relate() API
- Preserve batch operations (addNouns, addVerbs) as they remain current
- Mark deprecated methods in both source and compiled definitions

Migration guide:
- addNoun(data, type, metadata) → add(data, { nounType: type, ...metadata })
- addVerb(source, target, type, metadata) → relate(source, target, type, metadata)

docs/guides/model-loading.md

@@ -302,7 +302,7 @@ const response = await openai.embeddings.create({
 // After: Local Brainy embeddings
 const brain = new BrainyData()
 await brain.init() // One-time setup
-const id = await brain.addNoun("Your text", 'content') // Embedded automatically
+const id = await brain.add("Your text", { nounType: 'content' }) // Embedded automatically
 ```
 
 ### From Sentence Transformers