Copy Paste
This notebook covers how to load a document object from something you just want to copy and paste. In this case, you don't even need to use a DocumentLoader, but rather can just construct the Document directly.
from langchain.docstore.document import Document
text = "..... put the text you copy pasted here......"
doc = Document(page_content=text)
Metadata
If you want to add metadata about the where you got this piece of text, you easily can with the metadata key.
metadata = {"source": "internet", "date": "Friday"}
doc = Document(page_content=text, metadata=metadata)