Small improvements and fixes

• No longer uses a LayoutBuilder internally, and thus will work with intrinsic widgets.
• Removed unused flutter assets in pubspec that caused errors at build #4
• Updated some tests to work with new golden_toolkit and the GitHub actions to use the same flutter version as locally.

Responsive Grid & Fluid Text

• Responsive grid utilities and documentation
• Fluid text and documentation

Initial release

0.0.1

Update README.md