extensions/markdown-language-features/server/src/workspace.ts/VsCodeClientWorkspace/doDeleteDocument
class VsCodeClientWorkspace:	private doDeleteDocument(uri: URI) {
		this.logger.log(md.LogLevel.Trace, 'VsCodeClientWorkspace: deleteDocument', `${uri}`);

		this._documentCache.delete(uri);
		this._onDidDeleteMarkdownDocument.fire(uri);
	}