docs: Update brain documentation and images (#2475)

This pull request updates the documentation and images for the default
brain in Quivr. It includes instructions on how to get started,
customize the brain, and ask questions. Additionally, it adds
documentation for the GPT-4 brain and provides steps on how to interact
with it.

docs/brains/docs-and-urls.mdx

@@ -4,3 +4,37 @@ description: Docs and URLs
 icon: file
 ---
 
+## Docs and URLs
+
+This is the default brain that comes with Quivr. It is a simple brain that is used to answer questions about your files and URLs.
+
+### How to get started ? 👀
+
+<Steps>
+    <Step title="Create a brain">
+        Go to [Quivr](https://chat.quivr.app) and create a brain
+        ![Create a brain](/images/create-brain-doc.png)
+    </Step>
+    <Step title="Enter a name and a description">
+        The better your description, the better Quivr will be at finding your brain when you ask questions.
+        ![Enter a name and a description](/images/brain-name-description.png)
+    </Step>
+    <Step title="Upload your docs or URLS">
+        You can upload your docs or URLS by clicking on the "Upload" button.
+        ![Upload your docs or URLS](/images/upload-docs-urls.png)
+    </Step>
+    <Step title="Customize your Brain">
+        You can customize:
+        - The name of your brain
+        - The description of your brain
+        - The model that your brain uses (GPT3.5 or GPT4)
+        - The prompt of your brain
+    </Step>
+    <Step title="Ask Questions to your Brain">
+        Ask your Brain questions about the knowledge that you provide.
+        Simply **@brain** followed by your question.
+    </Step>
+</Steps>
+
+
+You now have a brain that can answer questions about your files and URLs. You can ask your brain questions by typing **@brain** followed by your question.

docs/brains/gpt4.mdx

@@ -4,4 +4,23 @@ description: GPT-4
 icon: brain
 ---
 
-Talk to GPT4 via Quivr
+## GPT-4
+
+This is a brain that allows you to interact with GPT-4. You can ask questions to GPT-4 and get answers in real-time.
+
+### How to get started ? 👀
+
+<Steps>
+    <Step title="Create a brain">
+        Go to [Quivr](https://chat.quivr.app) and create a brain.
+    </Step>
+    <Step title="Choose GPT-4">
+        Choose GPT-4 as your brain.
+    </Step>
+    <Step title="Ask a question to GPT-4">
+        Ask a question to GPT-4 by typing **@brain** followed by your question.
+    </Step>
+</Steps>
+
+You now have a brain that can answer questions using GPT-4. You can ask your brain questions by typing **@brain** followed by your question. 
+

docs/intro.mdx

@@ -1,6 +1,7 @@
 ---
 title: Overview
 description: Quivr is an open source RAG framework to deploy and use **AI assistants**
+icon: forward
 ---
 
 Welcome to the documentation of Quivr! This is the place where you’ll find help, guidance and support for collaborative software development. Whether you’re involved in an open-source community or a large software team, these resources should get you up and running quickly!

docs/mint.json

@@ -71,7 +71,7 @@
       "pages": [ "brains/docs-and-urls","brains/gpt4", "brains/sql"]
     },
     {
-      "group": "Agents",
+      "group": "Assistants",
       "pages": ["agents/summary"]
     }
   ],