feat(Tools): Adds the Subversion client to the Dev Container (#35)

- Fixes #31
- Adds the local Subversion client support.

.devcontainer/devcontainer.json

@@ -18,6 +18,7 @@
     },
     "ghcr.io/devcontainers/features/git:1": {},
     "ghcr.io/devcontainers/features/github-cli:1": {},
+    "./local-features/subversion": "latest",
     "./local-features/wp-cli": "latest",
     "./local-features/php-cli-xdebug": "latest"
   },
@@ -28,6 +29,7 @@
     "ghcr.io/devcontainers/features/docker-in-docker",
     "ghcr.io/devcontainers/features/git",
     "ghcr.io/devcontainers/features/github-cli",
+    "./local-features/subversion",
     "./local-features/wp-cli",
     "./local-features/php-cli-xdebug"
   ]

.devcontainer/local-features/subversion/devcontainer-feature.json

@@ -0,0 +1,8 @@
+{
+    "Id": "subversion",
+    "name": "Install the Subversion CLI",
+    "install": {
+        "app": "",
+        "file": "install.sh"
+    }
+}

.devcontainer/local-features/subversion/install.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+set -eux
+
+export DEBIAN_FRONTEND=noninteractive
+
+# Install the Subversion CLI.
+if [ ! -f /usr/bin/svn ]; then
+	echo "Installing Subversion CLI..."
+	sudo apt-get update -y --no-install-recommends
+	sudo apt-get install -y --no-install-recommends subversion
+fi
+
+echo "Done!"