Issue Type: <b>Bug</b> The syntax highlighter breaks when defining an `interface`, because interface methods have no body.  VS Code version: Code - Insiders 1.53.0-insider (c927a8015b9e26bd454d6e293bb0384aa1975d06, 2020-12-18T05:27:48.567Z) OS version: Windows_NT x64 10.0.19042 <!-- generated by issue reporter -->