Add support for web-based VSCode

VSCode has a [web version](https://code.visualstudio.com/docs/editor/vscode-web). A typical use case for this is github.dev, accessed by pressing the `.` hotkey in any repo. AGLint supports the browser environment, however, project scanning should be solved with another API, since it is not possible to use Node.js specific API in the browser environment. In the `package.json` file, we should specify a `browser` entry point in addition to `main`.

References:
- GitHub dev: https://github.com/github/dev / https://github.dev
- Documentation: https://code.visualstudio.com/api/extension-guides/web-extensions
- Sample: https://github.com/microsoft/vscode-extension-samples/tree/main/lsp-web-extension-sample
- Testing: https://github.com/microsoft/vscode-test-web