annotate the devcontainer

Author: Craig Peters

.devcontainer/devcontainer.json

@@ -1,21 +1,34 @@
 {
+ // See the devcontainer spec at https://containers.dev/implementors/spec/
+ "name": "React Codespaces Template",
+
+ // Container image to build environment from
+ // universal contains many tools making it useful in many contexts https://github.com/devcontainers/images/tree/main/src/universal
  "image": "mcr.microsoft.com/devcontainers/universal:2",
+
+ // Specify the minimum machine spec for running the dev container
  "hostRequirements": {
  "cpus": 4
  },
- "waitFor": "onCreateCommand",
+
+ // Upon Codespaces or image prebuild, refresh the npm and node.hs installation (async from environment creation)
  "updateContentCommand": "npm install",
- "postCreateCommand": "",
+
+ // Upon environment create, and after the user session is created, run the server
  "postAttachCommand": {
  "server": "npm start"
  },
+
  "customizations": {
+ // Configure Codespaces to open the application source on start
  "codespaces": {
  "openFiles": [
  "src/App.js"
  ]
  }
  },
+
+ // Configure the environment to open a browser to the application on port 3000
  "portsAttributes": {
  "3000": {
  "label": "Application",