[AUR-390] Add prompt template and prompt component (#24)

* Export pipeline to config

* Export the input to config

* Preliminary creating UI dynamically

* Add test for config export

* Try out prompt UI

* Add example projects

* Fix test errors

* Standardize interface for retrieval

* Finalize the UI demo

* Update README.md

* Update README

* Refactor according to main

* Fix typing issue

* Add openai key to git-secret

* Add prompt template and prompt component

* Update test

* update tests

* revert docstring

---------

Co-authored-by: trducng <trungduc1992@gmail.com>
Co-authored-by: Nguyen Trung Duc (john) <john@cinnamon.is>

knowledgehub/documents/base.py

@@ -22,6 +22,9 @@ class Document(BaseDocument):
         text = self.text
         return HaystackDocument(content=text, meta=metadata)
 
+    def __str__(self):
+        return self.text
+
 
 class RetrievedDocument(Document):
     """Subclass of Document with retrieval-related information