Two corrections to the "Icons" page

[DAnn2012]

Platforms affected

"Icons" page (iOS and Electron)

Motivation and Context

1. The "density" parameter is for Android not for iOS
2. The correct value is "app" not "application"

Description

1. Removed "density" from the example
2. Corrected from "application" to "app"

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[DAnn2012]

Hello @NiklasMerz

When are you planning to review these changes of mine?

Thank you.

[DAnn2012]

Hello @erisu

When are you planning to review these changes of mine?

Thank you.