Update dev container build, incl. dotfiles and cache-bust

.devcontainer/devcontainer.json

@@ -1,7 +1,11 @@
 {
   "name": "React Dev Container",
   "build": {
-    "dockerfile": "Dockerfile"
+    "dockerfile": "Dockerfile",
+    "args": {
+      // Set CACHE_BUST in your local env when you want to force a rebuild
+      "CACHE_BUST": "${localEnv:CACHE_BUST}"
+    }
   },
   "customizations": {
     "vscode": {
@@ -21,6 +25,6 @@
       "onAutoForward": "notify"
     }
   },
-  "postCreateCommand": "npm install",
+  //"postCreateCommand": "npm install",
   "remoteUser": "node"
 }