Message Formatting: user mention rendered as `mailto` link

[That-Guy977]

Description

In Developer Docs > Reference, the formats table shows a structure and example. The example for a user mention is rendered as a link with a mailto uri, specifically mailto:@80351110224678912

Steps to Reproduce

Visit Developer Docs > Reference and view the Formats table.

Expected Behavior

The user mention example is rendered as plaintext <@80351110224678912>, like other mention examples.

Current Behavior

The user mention example is rendered as a link mailto:@80351110224678912.

Screenshots/Videos

Client and System Information

Google Chrome 116.0.5845.187 MacOS Mojave 10.14.6 / Darwin 18.7.0