toX, mapContextInX added and more

[lue-bird]

What's different from the existing open PR?

• no embed functions
  • functionality is covered well enough by

    with (\context -> ... |> element)

  • ↑ is more generic, meaning it allows different
    msg, Option value etc. types and avoids ↓
• no separate embed module
  • no embed functions exist
    apart from element etc. that aren't in a dedicated module
  • circular imports forced a moving types to internal.
    This has the side effect of forcing a major version bump
• the run functions for which you considered exposing useful
  are called toX instead of unwrapX
  • as suggested
• withX, fromX functions for Element.WithContext.Input Label, Thumb, Option, Placeholder
  • providing the same functionality as for element, attribute
  • to embed elements with a different context type
• mapContextInX functions for element, attribute, Element.WithContext.Input Label, Thumb, Option, Placeholder
• more documentation
• corrections to broken links, spelling and type variable names

To discuss

• mapContextInX's name: maybe mapContextForX, xOverMappedContext, xOverContext, xOver, other suggestions very welcome!

[miniBill]

Thank you for the PR! I will try to have a look at it soon!