`a`, `form`, `img`, `input`, `label`, `option`, `progress`, `select`, and `textarea` are now just regular elements (without helper parameters), because:
- Sometimes the use case doesn't fit (`a` as anchor without href, for example)
- There's no reason these are special among the others, so streamlining them makes sense
Also added new attributes `action`, `alt`, `for`, `method` that I had somehow missed.
This makes it easier to use dot-imports.
Also updated the readme and examples with new usage, and move the `Classes` helper into the `components` package.
