4.0.0 - SwiftUI additions and addressing some pain points

This release of Fluxor contains some additions related to SwiftUI and addresses some pain points and CI issues

• The Store able to subscribe to Action publishers
• Makes SwiftUI bindings simpler and easier to create
• Guides added to documentation
• Internal tests are now less flaky on the CI
• Documentation link fixes

Pull requests

• Make the Store able to subscribe to Action publishers (#85)
• Make tests less flaky (#86)
• Make Action not conform to Encodable (#84)
• Increase wait time in tests (#83)
• Make environment public on the Store (#82)
• Simpler bindings (#81)
• Documentation coverage badge and CNAME (#80)
• Fix broken link in README (#79) - Thanks @sgrgrsn
• Docs badge link to fluxor.dev (#78)
• Add CNAME (#77)
• FluxorExplorer App Store badge (#76)
• Add guides (#75)