Make Nix feature in devcontainer optional (#63)

Author: spenserblack

.devcontainer/devcontainer.json

@@ -4,9 +4,6 @@
     "dockerfile": "Dockerfile",
     "args": { "VARIANT": "1" }
   },
-  "features": {
-    "ghcr.io/devcontainers/features/nix:1": {}
-  },
   "customizations": {
     "vscode": {
       "extensions": [

.devcontainer/nix/devcontainer.json

@@ -0,0 +1,22 @@
+{
+  "name": "With Nix",
+  "build": {
+    "dockerfile": "../Dockerfile",
+    "args": { "VARIANT": "1" }
+  },
+  "features": {
+    "ghcr.io/devcontainers/features/nix:1": {}
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "EditorConfig.EditorConfig",
+        "rust-lang.rust-analyzer",
+        "sumneko.lua",
+        "tomoyukim.vscode-mermaid-editor"
+      ]
+    }
+  },
+  "onCreateCommand": "./scripts/setup-git.sh",
+  "remoteUser": "vscode"
+}