chore(devcontainer): drop requirement for docker-compose and use devcontainer.json settings directly

.devcontainer/devcontainer.json

@@ -1,16 +1,50 @@
 {
     "name": "gluetun-dev",
-    "dockerComposeFile": [
-        "docker-compose.yml"
+    // User defined settings
+    "containerEnv": {
+        "TZ": ""
+    },
+    // Fixed settings
+    "build": {
+        "dockerfile": "./Dockerfile"
+    },
+    "postCreateCommand": "~/.windows.sh && go mod download",
+    "capAdd": [
+        "NET_ADMIN", // Gluetun specific
+        "SYS_PTRACE" // for dlv Go debugging
     ],
-    "service": "vscode",
-    "runServices": [
-        "vscode"
+    "securityOpt": [
+        "seccomp=unconfined" // for dlv Go debugging
+    ],
+    "mounts": [
+        // Zsh commands history persistence
+        {
+            "source": "${localEnv:HOME}/.zsh_history",
+            "target": "/root/.zsh_history",
+            "type": "bind"
+        },
+        // Git configuration file
+        {
+            "source": "${localEnv:HOME}/.gitconfig",
+            "target": "/root/.gitconfig",
+            "type": "bind"
+        },
+        // SSH directory for Linux, OSX and WSL
+        // On Linux and OSX, a symlink /mnt/ssh <-> ~/.ssh is
+        // created in the container. On Windows, files are copied
+        // from /mnt/ssh to ~/.ssh to fix permissions.
+        {
+            "source": "${localEnv:HOME}/.ssh",
+            "target": "/mnt/ssh",
+            "type": "bind"
+        },
+        // Docker socket to access the host Docker server
+        {
+            "source": "/var/run/docker.sock",
+            "target": "/var/run/docker.sock",
+            "type": "bind"
+        }
     ],
-    "shutdownAction": "stopCompose",
-    "postCreateCommand": "~/.windows.sh && go mod download && go mod tidy",
-    "workspaceFolder": "/workspace",
-    // "overrideCommand": "",
     "customizations": {
         "vscode": {
             "extensions": [