🐛 Bug Report

Current behavior

amp-list example on playground.amp.dev has validation error due to missing ">" after the html tag.

Please also provide:

• Page link: https://playground.amp.dev/?url=https%3A%2F%2Fpreview.amp.dev%2Fdocumentation%2Fexamples%2Fcomponents%2Famp-list&format=websites&_gl=1*1k4ai1c*_ga*YW1wLVhoSm1JRjNVaXRJeDZDeDhWbWNBOEE.
• (Optional) Screenshots/videos:

Expected behavior/code

There should be no validation errors.

Reproduction procedure

Please provide the steps to reproduce the problem:

1. Load https://playground.amp.dev/?url=https%3A%2F%2Fpreview.amp.dev%2Fdocumentation%2Fexamples%2Fcomponents%2Famp-list&format=websites&_gl=1*1k4ai1c*_ga*YW1wLVhoSm1JRjNVaXRJeDZDeDhWbWNBOEE. on any browser & OS