Add basic devcontainer configuration

Signed-off-by: Marek Pikuła <marek.pikula@embevity.com>

.devcontainer/devcontainer.json

@@ -0,0 +1,36 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/python
+{
+	"name": "Headscale WebUI",
+	"image": "mcr.microsoft.com/devcontainers/python:0-3",
+	"features": {
+		"ghcr.io/meaningful-ooo/devcontainer-features/fish:1": {},
+		"ghcr.io/devcontainers-contrib/features/poetry:2": {
+			"version": "latest"
+		}
+	},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "pip3 install --user -r requirements.txt",
+
+	// Configure tool-specific properties.
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"bungcip.better-toml",
+				"github.vscode-github-actions"
+				"GitHub.vscode-pull-request-github",
+				"mhutchie.git-graph",
+				"ms-azuretools.vscode-docker",
+				"njpwerner.autodocstring",
+				"redhat.vscode-yaml",
+			]
+		}
+	}
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}