extensions/markdown-language-features/src/languageFeatures/pathCompletions.ts/MdVsCodePathCompletionProvider/resolveReference
class MdVsCodePathCompletionProvider:	private resolveReference(document: ITextDocument, ref: string): vscode.Uri | undefined {
		const docUri = this.getFileUriOfTextDocument(document);

		if (ref.startsWith('/')) {
			const workspaceFolder = vscode.workspace.getWorkspaceFolder(docUri);
			if (workspaceFolder) {
				return vscode.Uri.joinPath(workspaceFolder.uri, ref);
			} else {
				return this.resolvePath(docUri, ref.slice(1));
			}
		}

		return this.resolvePath(docUri, ref);
	}