`comment_references` has trouble with images and links

[goderbauer]

The comment_references fires on the following lines even though it shouldn't:

• https://github.com/flutter/flutter/blob/44622dac46a954b38111fc6ec1de6e2c74065de3/packages/flutter/lib/src/semantics/semantics.dart#L2424-L2425
• https://github.com/flutter/flutter/blob/44622dac46a954b38111fc6ec1de6e2c74065de3/packages/flutter/lib/src/services/autofill.dart#L595-L596

[goderbauer]

cc @srawlins