docs: add EMBEDDINGS_TYPE valid options to README and .env.example

Signed-off-by: YASHBHIWANIA <yashbhiwania772@gmail.com>

Author: YASHBHIWANIA

README.md

@@ -63,6 +63,7 @@ git clone https://github.com/The-OpenROAD-Project/ORAssistant.git
 ```
 
 **Step 2**: Copy the `.env.example` file, and update your `.env` file with the appropriate API keys.
+> **Note:** When configuring `EMBEDDINGS_TYPE`, valid options are `HF`, `GOOGLE_GENAI`, or `GOOGLE_VERTEXAI`. If using `HF`, no API key is needed but startup is slower. If using `GOOGLE_GENAI`, ensure `GOOGLE_API_KEY` is set.
 
 Modify the Docker `HEALTHCHECK_` variables based on the hardware requirements.
 If you have a resource-constrained PC, try increasing `HEALTHCHECK_START_PERIOD` to a value large
@@ -99,6 +100,7 @@ uv sync
 ```
 
 **Step 2**: Copy the `.env.example` file, and update your `.env` file with the appropriate API keys.
+> **Note:** When configuring `EMBEDDINGS_TYPE`, valid options are `HF`, `GOOGLE_GENAI`, or `GOOGLE_VERTEXAI`. If using `HF`, no API key is needed but startup is slower. If using `GOOGLE_GENAI`, ensure `GOOGLE_API_KEY` is set.
 
 ```bash
 cd backend

backend/.env.example

@@ -22,6 +22,7 @@ GOOGLE_GEMINI=2.0_flash
 
 LLM_TEMP=1
 
+# Choose embeddings type (options: HF, GOOGLE_GENAI, GOOGLE_VERTEXAI)
 EMBEDDINGS_TYPE=GOOGLE_GENAI
 GOOGLE_EMBEDDINGS=gemini-embedding-001
 HF_EMBEDDINGS=thenlper/gte-large