feat: add output-format option (md or json) and exporter of questions…

[Symbolk]

… with codebase context

Example usage with the new json format:

export --output-dir "~/cursor-chat-export/data" --output-format json

Example output of md with context:

# Chat Transcript - Tab 1

## User:


[text]  
@Codebase Summarize this project


[context]
- README.md: 0.47
- packages/core/src/indexing/chunk/ChunkCodebaseIndex.ts: 0.46
- packages/core/src/context/providers/CodebaseContextProvider.ts: 0.45
- packages/core/src/indexing/CodeSnippetsIndex.ts: 0.45
- packages/core/src/indexing/CodebaseIndexer.ts: 0.44
- packages/core/src/indexing/FullTextSearchCodebaseIndex.ts: 0.42
- packages/core/src/indexing/TestCodebaseIndex.ts: 0.42
- packages/core/src/indexing/README.md: 0.4

Example output of json with context:

[
  {
    "user": {
      "text": "@Codebase Summarize this project",
      "context": [
        {
          "file": {
            "relativeWorkspacePath": "README.md"
          },
          "score": 0.46909475326538086
        },
        {
          "file": {
            "relativeWorkspacePath": "packages/core/src/indexing/chunk/ChunkCodebaseIndex.ts"
          },
          "score": 0.45642781257629395
        }
	  ]
	}
   },
  {
    "ai": {
      "model": "gpt-4o-mini",
      "text": ""
    }
  },
]

[proxseas]

This is a significant improvement.