Documentation for Backend (#120)

* docs: added documentation for Google, HuggingFace and LangChain

* docs: added assets for documentation

* chore: removed assets to avoid CI issues

---------

Signed-off-by: Kannav02 <kannavsethi02@gmail.com>
Co-authored-by: Song Luar <espsluar@gmail.com>

Author: Kannav02

backend/README.md

@@ -0,0 +1,116 @@
+# Backend For ORAssistant
+
+This folder contains the backend code for the ORAssistant. Follow the instructions below to set up the environment and run the backend.
+
+## Preparing the Environment Variables
+
+To configure the application, you'll need to set up the environment variables in your `.env` file:
+
+The given command would copy the template for environment variables to a local `.env` file 
+
+
+```
+cp .env.example .env
+```
+
+
+### Setting Up Google API Key and Credentials Variables
+
+There are 2 variables that needs to be set up
+
+- `GOOGLE_API_KEY`
+
+This key is used to access the various google cloud functions.
+  - Go to [Google Cloud Console](https://console.cloud.google.com/)
+  - Create new project or select existing one
+  - Enable required APIs:
+       - Google Gemini API
+       - Vertex AI API
+  - Go to APIs & Services > Credentials
+  - Click "Create Credentials" > "API Key"
+  - Copy the generated key and it to the `.env` file
+  
+- `GOOGLE_APPLICATION_CREDENTIALS`
+  Since most of the GCP functions / services would be used by our app, we need to have a special credential that would allow `ORAssistant`'s access to the GCP
+    Steps to set up Service Account Credentials:
+  - In Google Cloud Console, go to IAM & Admin > Service Accounts
+  - Click "Create Service Account"
+  Fill in service account details
+  -  Grant required roles:
+       - Vertex AI User
+       - Vertex AI Service Agent
+  - Create key (JSON format)
+  - Download JSON file
+  - Store securely and add path to .env:
+       `GOOGLE_APPLICATION_CREDENTIALS=/path/to/credentials.json`
+
+**NOTE**: The user might need billing to be set up on google cloud account and make sure to name the file as `credentials.json`  as this would be ignored by `.git` and wouldn't be exposed on Github
+
+### Setting Up LangChain Variables
+
+There are 4 variables that needs to be set up
+
+- `LANGCHAIN_TRACING_V2` 
+  
+  This is used to enable LangChain's debugging and monitoring features,
+  can be set to either `true` or `false`
+
+- `LANGCHAIN_ENDPOINT`
+  
+  The URL endpoint for LangSmith (LangChain's monitoring platform). 
+  Default value should be `https://api.smith.langchain.com` for cloud-hosted LangSmith.
+  Used to send trace data, metrics, and debugging information from your LangChain applications.
+
+- `LANGCHAIN_API_KEY`
+  
+    API key required to authenticate with LangSmith platform.
+  - Get your key from: https://smith.langchain.com/
+  - Create account if you don't have one
+  - Navigate to Settings > API Keys
+  - Create new API key
+  - Format: starts with `lsv2_` followed by a unique string
+  
+- `LANGCHAIN_PROJECT`
+    
+    Project identifier in LangSmith to organize and track your traces.
+  - Create new project in LangSmith dashboard
+  - Use the project name or ID provided
+  - Example: "my-rag-project"
+  - Helps organize different applications/environments
+  - Multiple apps can share same project
+  
+
+### Setting Up Huggingface User Access Token
+
+To set up the `HF_TOKEN` variable in `.env` file , go through the following instructions:
+
+- Go the official website for [Huggingface](https://huggingface.co/) and either Login or Sign up.
+- On the main page click on user access token
+- Click on create access token
+- Provide only Read Instruction for the token and Click on Generate Token
+  
+  
+
+
+Provide the value for `HF_TOKEN` with the token that is generated
+
+## Running the Application
+
+### Install Required Packages
+
+Ensure you have the necessary dependencies installed by running:
+
+```bash
+pip install -r requirements.txt
+```
+### Docker Command
+
+If you want to run an isolated container for backend, you can use the following command 
+
+```bash
+docker build -t (image_name) .
+```
+
+Make sure you are in the backend folder before running the above command.
+
+**NOTE**: The project does support a `docker-compose` file that would run all of the containers together