icon 1.0.0+2

An extended Icon for those that are not actually square. Plus shadows support!

[1.0.0+2] - 25 FEB 21

• Looked back at the base Icon class and recognized that IconToo ought to support TextDirection, allow a Key initialization, and properly accept and pass a semanticLabel.
• Added a second demo to the Icon Example app.
• Altered some documentation based on hover hints and DartDoc.
• Updated README presentation and sample code.

[0.1.0+1] - 25 FEB 21

• Initial release as a transfer from an Android application on which I am primarily focused.