Remembrall Integration (#10767)

- **Description:** Added integration instructions for Remembrall. 
  - **Tag maintainer:** @hwchase17 
  - **Twitter handle:** @raunakdoesdev

Fun fact, this project originated at the Modal Hackathon in NYC where it
won the Best LLM App prize sponsored by Langchain. Thanks for your
support 🦜

docs/extras/integrations/memory/remembrall.md

@@ -0,0 +1,53 @@
+# Remembrall
+
+This page covers how to use the [Remembrall](https://remembrall.dev) ecosystem within LangChain.
+
+## What is Remembrall?
+
+Remembrall gives your language model long-term memory, retrieval augmented generation, and complete observability with just a few lines of code.
+
+![Remembrall Dashboard](/img/RemembrallDashboard.png)
+
+It works as a light-weight proxy on top of your OpenAI calls and simply augments the context of the chat calls at runtime with relevant facts that have been collected.
+
+## Setup
+
+To get started, [sign in with Github on the Remembrall platform](https://remembrall.dev/login) and copy your [API key from the settings page](https://remembrall.dev/dashboard/settings).
+
+Any request that you send with the modified `openai_api_base` (see below) and Remembrall API key will automatically be tracked in the Remembrall dashboard. You **never** have to share your OpenAI key with our platform and this information is **never** stored by the Remembrall systems.
+
+### Enable Long Term Memory
+
+In addition to setting the `openai_api_base` and Remembrall API key via `x-gp-api-key`, you should specify a UID to maintain memory for. This will usually be a unique user identifier (like email).
+
+```python
+from langchain.chat_models import ChatOpenAI
+chat_model = ChatOpenAI(openai_api_base="https://remembrall.dev/api/openai/v1",
+                        model_kwargs={
+                            "headers":{
+                                "x-gp-api-key": "remembrall-api-key-here",
+                                "x-gp-remember": "user@email.com",
+                            }
+                        })
+
+chat_model.predict("My favorite color is blue.")
+import time; time.sleep(5)  # wait for system to save fact via auto save
+print(chat_model.predict("What is my favorite color?"))
+```
+
+### Enable Retrieval Augmented Generation
+
+First, create a document context in the [Remembrall dashboard](https://remembrall.dev/dashboard/spells). Paste in the document texts or upload documents as PDFs to be processed. Save the Document Context ID and insert it as shown below.
+
+```python
+from langchain.chat_models import ChatOpenAI
+chat_model = ChatOpenAI(openai_api_base="https://remembrall.dev/api/openai/v1",
+                        model_kwargs={
+                            "headers":{
+                                "x-gp-api-key": "remembrall-api-key-here",
+                                "x-gp-context": "document-context-id-goes-here",
+                            }
+                        })
+
+print(chat_model.predict("This is a question that can be answered with my document."))
+```