Fix the devcontainer to work with Github Codespaces

Author: mrinalwadhwa

.devcontainer/devcontainer.json

@@ -1,4 +1,13 @@
 {
-  "name": "Autonomy Builder",
-  "image": "ghcr.io/build-trust/autonomy-builder"
+  "image": "mcr.microsoft.com/devcontainers/typescript-node:0-18",
+  "features": {
+    "ghcr.io/devcontainers/features/nix:1": {
+      "extraNixConfig": "experimental-features = nix-command flakes, download-buffer-size = 268435456"
+    }
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": ["mkhl.direnv"]
+    }
+  }
 }