build: add VS Code DevContainer support for seamless onboarding

.devcontainer/devcontainer.json

@@ -0,0 +1,21 @@
+{
+    "name": "OpenROAD Dev Environment",
+    "build": {
+        "dockerfile": "../Dockerfile",
+        "target": "dev",
+        "context": ".."
+    },
+    "customizations": {
+        "vscode": {
+            "settings": {
+                "terminal.integrated.defaultProfile.linux": "bash"
+            },
+            "extensions": [
+                "ms-vscode.cpptools-extension-pack",
+                "twxs.cmake"
+            ]
+        }
+    },
+    "remoteUser": "root",
+    "postCreateCommand": "echo 'Welcome to the OpenROAD DevContainer! Run ./etc/Build.sh to get started.'"
+}

docs/user/Build.md

@@ -72,6 +72,19 @@ Now you are ready to install the prebuilt binaries.
 Please refer to the instructions for installing prebuilt binaries 
 [above](#build-with-prebuilt-binaries).
 
+
+## VS Code DevContainer (Optional)
+
+For VS Code users, a `.devcontainer/devcontainer.json` configuration is available in the repository root. This provides a zero-friction development setup — simply open the repo in VS Code and select "Reopen in Container".
+
+**Limitations:**
+- No GUI support (OpenROAD GUI will not work inside the container)
+- Requires VS Code with the Dev Containers extension installed
+- Not recommended as a primary onboarding path — use Docker or Build Locally instead
+
+This is purely optional and does not affect any existing workflows.
+
+
 ## Build Locally
 
 The default build type is `RELEASE` to compile optimized code.