feat: add configuration for GitHub CodeSpaces (aws#10470)

Add `.devcontainer.json` referencing the existing `.gitpod.yml` for supporting GitHub codespaces

closes aws#10447 

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: ayush987goyal

.devcontainer.json

@@ -0,0 +1,8 @@
+{
+    "name": "Dev Container Definition - AWS CDK",
+    "image": "jsii/superchain",
+    "postCreateCommand": "yarn build --skip-test --no-bail --skip-prereqs --skip-compat",
+    "extensions": [
+        "dbaeumer.vscode-eslint@2.1.5"
+    ]
+}