Provide devcontainer configuration

.devcontainer/devcontainer.json

@@ -4,8 +4,13 @@
   "dockerComposeFile": "../docker-compose.yml",
   "service": "app",
   "workspaceFolder": "/app",
+  "containerEnv": {
+    "EDITOR": "code -w"
+  },
   // Replace the standard command with a noop to allow exec-ing
   "overrideCommand": true,
+  // Git complains if user IDs don't match, which they will with a mounted directory
+  "onCreateCommand": "git config --global --add safe.directory /app",
   // Port forwarding
   "forwardPorts": [
     2342,
@@ -26,6 +31,16 @@
   // VSCode additions
   "features": {},
   "customizations": {
-    "vscode": {}
+    "vscode": {
+      "extensions": [
+        "dbaeumer.vscode-eslint",
+        "EditorConfig.EditorConfig",
+        "github.vscode-github-actions",
+        "ms-python.python",
+        "ms-python.black-formatter",
+        "ms-python.flake8",
+        "ms-python.mypy-type-checker"
+      ]
+    }
   }
 }

README.md

@@ -49,6 +49,23 @@ To delete all data and start over fresh you can use `docker compose down`.
 Management commands can be listed and run using the `./flask` command, which
 forwards them to the flask command line within the container.
 
+### Visual Studio Code
+
+If you use Visual Studio Code it should present you with the option to open the
+project in a dev container. If not, run `code .` from your local copy, and ensure
+you have the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) installed.
+
+Reopening in a dev container will start everything via Docker, attach
+your VSCode instance to the application container, install relevant extensions,
+and ensure everything is configured to fit with our standards.
+
+The first time you start the dev container you will need to tell VSCode where to
+find the Poetry virtual environment. You can do this by open the command pallette
+(Cmd-P on macOS devices) and searching for "Python: Select interpreter", the list
+presented should include `website-${randomHash}-py3.11`, which will be annotated
+as "Poetry". Select that, and then any Python tooling and shells will run within
+the appropriate virtualenv.
+
 ### Errors starting the dev server
 
 e.g. `Error: While importing 'dev_server', an ImportError was raised.`