[nit] Update Create JSON and Create YAML button commands

VSCode walkthroughs automatically format things in pretty blue boxes whenever you have a single command per newline

## Before

<img width="588" alt="Screenshot 2024-02-21 at 15 43 46" src="https://github.com/lastmile-ai/aiconfig/assets/151060367/1f41b509-8b68-438e-a70a-fbfa8bf41b9e">

## After

<img width="599" alt="Screenshot 2024-02-21 at 16 57 59" src="https://github.com/lastmile-ai/aiconfig/assets/151060367/451d3ad3-638b-4e6e-b61a-622f84d64be7">

vscode-extension/package.json

@@ -137,8 +137,8 @@
 					},
           {
 						"id": "createAIConfig",
-						"title": "Create an AIConfig file",
-						"description": "You can do this either in JSON or YAML format. This file defines the AI models and workflow you want to use in your project.\n[JSON](command:vscode-aiconfig.createAIConfigJSON) [YAML](command:vscode-aiconfig.createAIConfigYAML)",
+						"title": "Create your first AIConfig",
+						"description": "You can do this either in JSON or YAML format. This file defines the AI models and workflow you want to use in your project.\n[Create .aiconfig.yaml](command:vscode-aiconfig.createAIConfigYAML)\nIf you prefer JSON:\n[Create .aiconfig.json](command:vscode-aiconfig.createAIConfigJSON)",
 						"media": {
               "markdown": "media/welcomePage.md"
 						}