…ints

Container class auto-generates responsive max-width styles for all Tailwind
breakpoints. This was creating 1280/1440 min-width breakpoints in projects
that use mobile-first (max-width) approach.

Changes:
- Filter container's min-width max-width styles unless user already has
  min-width breakpoints in their project
- Explicit xl:/2xl: classes still create min-width breakpoints as expected
- Add tailwindBreakpoints constant with all 7 breakpoints for parsing
- Fix typo: styleDeckKey -> styleDeclKey
- Use shorthand properties where applicable

Tests added:
- container class without/with user min-width breakpoints
- explicit xl: class creates min-width breakpoint
- container combined with explicit xl: class
- verify breakpoints array contains only needed breakpoints

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