Cards: unable to render D. M. YYYY date properly

Screenshots

When Title or Subtitle in HeroCard starts with date in European format (D. M. YYYY):

It gets evaluated with Markdown as ordered list and produces wrong HTML:

Version

• webchat-stable
• Bot Framework emulator

Describe the bug

When Title or Subtitle in HeroCard begins with date in the form of D. M. YYYY it's recognized as Markdown ordered list and rendered completely out of place (see screenshots).

To Reproduce

Steps to reproduce the behavior:

1. Connect your bot to proper channel registration

2. Start Bot Framework Emulator or deploy web chat to a website

3. Make sure your regional settings are European D. M. YYYY

4. Generate a Hero Card and set Title and/or Subtitle to today's date

   var reply = stepContext.Context.Activity.CreateReply();
   var card = new HeroCard
   {
       Title = string.Format(DateTime.Now.ToShortDateString()),
       Subtitle = DateTime.Now.ToShortDateString(),
   };
   
   reply.Attachments.Add(card.ToAttachment());
   await stepContext.Context.SendActivityAsync(reply);
   

5. Send it to user

6. See incorrect display in Web Chat

Expected behavior

Date should be displayed properly, not as an ordered list.

Additional context

Workaround: Prepend date with invisible character ⁣

[Bug]