text: Title: docs: add docs for the dict() method
  Body: # Context
  
  we need to document the behavior of calling `dict()` on a BaseDoc. Especially with nested DocList.
  
  ```python
  class InnerDoc(BaseDoc):
      x: int
  
  class MyDoc(BaseDoc):
      l: DocList[InnerDoc]
  
  doc = MyDoc(l=[InnerDoc(x=1), InnerDoc(x=2)])
  print(f'{doc.dict()=}')
  #> doc_view.dict()={'id': 'ab65fc52a60d1da1ce6196c100943e1f', 'l': [{'id': 'e218c3a6904cbbd0f48ccd10130c9f78', 'x': 1}, {'id': 'e30bf3d613bf5c3e805faf0c0dc0f704', 'x': 2}]}
  ```
  
  
  and we need to explain how using `dict(doc)` is different from using `doc.dict()`