build(elixir): add dev container

.devcontainer/devcontainer.json

@@ -0,0 +1,59 @@
+{
+  "name": "Elixir Phoenix Components",
+  "dockerComposeFile": "docker-compose.yml",
+  "service": "app",
+  "workspaceFolder": "/workspace",
+  // Features to install
+  "features": {
+    "ghcr.io/devcontainers/features/git:1": {},
+    "ghcr.io/devcontainers/features/github-cli:1": {}
+  },
+  // Use 'forwardPorts' to make a list of ports inside the container available locally.
+  "forwardPorts": [
+    4000,
+    5433
+  ],
+  // Configure tool-specific properties.
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "JakeBecker.elixir-ls",
+        "phoenixframework.phoenix",
+        "ms-vscode.vscode-json",
+        "bradlc.vscode-tailwindcss",
+        "ms-vscode.hexeditor",
+        "GitHub.copilot",
+        "GitHub.copilot-chat",
+        "ms-vscode.test-adapter-converter",
+        "hbenl.vscode-test-explorer",
+        "formulahendry.auto-rename-tag",
+        "esbenp.prettier-vscode"
+      ],
+      "settings": {
+        "terminal.integrated.defaultProfile.linux": "bash",
+        "elixirLS.dialyzerEnabled": true,
+        "elixirLS.fetchDeps": false,
+        "elixirLS.suggestSpecs": true,
+        "files.associations": {
+          "*.heex": "html",
+          "*.ex": "elixir",
+          "*.exs": "elixir"
+        },
+        "emmet.includeLanguages": {
+          "html": "html",
+          "elixir": "html"
+        },
+        "editor.formatOnSave": true,
+        "[elixir]": {
+          "editor.defaultFormatter": "JakeBecker.elixir-ls"
+        }
+      }
+    }
+  },
+  // Use 'postCreateCommand' to run commands after the container is created.
+  "postCreateCommand": "bash .devcontainer/setup.sh",
+  // Comment out to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+  "remoteUser": "vscode",
+  // Keep container running for faster subsequent starts
+  "shutdownAction": "stopContainer"
+}