Include .env in Docker build for easy llm setup (#2484)

Co-authored-by: Shuchang Zheng <shu@skyvern.com>

README.md

@@ -193,6 +193,7 @@ skyvern status
 1. Make sure you have [Docker Desktop](https://www.docker.com/products/docker-desktop/) installed and running on your machine
 1. Make sure you don't have postgres running locally (Run `docker ps` to check)
 1. Clone the repository and navigate to the root directory
+1. Run `skyvern init llm` to generate a `.env` file. This will be copied into the Docker image.
 1. Fill in the LLM provider key on the [docker-compose.yml](./docker-compose.yml). *If you want to run Skyvern on a remote server, make sure you set the correct server ip for the UI container in [docker-compose.yml](./docker-compose.yml).*
 2. Run the following command via the commandline:
    ```bash