Add devcontainer.json to configure the development container

* Specify the Docker image to use for the container
* Add necessary VS Code extensions for Python development
* Include a postCreateCommand to install dependencies from `requirements.txt`

devcontainer.json

@@ -0,0 +1,10 @@
+{
+    "name": "OmniParser Dev Container",
+    "image": "mcr.microsoft.com/devcontainers/python:3.9",
+    "extensions": [
+        "ms-python.python",
+        "ms-python.vscode-pylance",
+        "ms-toolsai.jupyter"
+    ],
+    "postCreateCommand": "pip install -r requirements.txt"
+}