Fix devcontainer invalid key

.devcontainer/devcontainer.json

@@ -19,7 +19,7 @@
     "postCreateCommand": "freqtrade create-userdir --userdir user_data/",
 
     "workspaceFolder": "/workspaces/freqtrade",
-
+    "customizations": {
         "settings": {
             "terminal.integrated.shell.linux": "/bin/bash",
             "editor.insertSpaces": true,
@@ -39,3 +39,4 @@
             "vscode-icons-team.vscode-icons",
         ],
     }
+}