fix: remove math.div to backward support

• fix sass deprecation errors related to division operation
• upgrade packages

• Publish website
• Update README

Notable Changes

• Move opacity property from block mixin to style-modifier mixin
• cursor and text-align property values passed as parameter in block mixin
• vertical-align property value passed as parameter in block mixin
• Add focus styles for accessibility
• Remove cursor: not-allowed disabled style
• Replace $buttono-background-color with more general color
• Allow changing the cursor if the button is not disabled
• Update README

v0.5.2...v1.0.1

• Documentation updates
• Upgraded dev dependencies