Fix image-minimizer on lines containing multiple images

[tom93]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

• Bugfix (dev facing)

Description of the changes in your PR

It is legal to have multiple images on a single line in Markdown. The previous regex did not handle that correctly. This PR fixes the regex.

Fixes the following issue(s)

• (Not tracked)

Testing

var exampleBody = "![image-1](https://x.githubusercontent.com/1/11111111111111111111111111111111.png) ![image-2](https://x.githubusercontent.com/2/22222222222222222222222222222222.png)";
await replaceAsync(exampleBody, REGEX_USER_CONTENT_IMAGE_LOOKUP, match => `<<${match}>>`);
// previous output (incorrect):
"<<![image-1](https://x.githubusercontent.com/1/11111111111111111111111111111111.png) ![image-2](https://x.githubusercontent.com/2/22222222222222222222222222222222.png)>>"
// output with the fix:
"<<![image-1](https://x.githubusercontent.com/1/11111111111111111111111111111111.png)>> <<![image-2](https://x.githubusercontent.com/2/22222222222222222222222222222222.png)>>" 

APK testing

N/A

Due diligence

• I read the contribution guidelines.

[Stypox]

Thank you!