New syntax for tag helpers i.e. tag.br instead of tag('br') #25195

[marekkirejczyk]

This is continuation of #25289.

New syntax for tag helpers. Avoid positional parameters and support HTML5 by default.
Example usage of tag helpers before:

tag(:br, nil, true)
content_tag(:div, content_tag(:p, "Hello world!"), class: "strong")

<%= content_tag :div, class: "strong" do -%>
  Hello world!
<% end -%>

Example usage of tag helpers after:

tag.br
tag.div tag.p("Hello world!"), class: "strong"

<%= tag.div class: "strong" do %>
  Hello world!
<% end %>

[rails-bot]

Thanks for the pull request, and welcome! The Rails team is excited to review your changes, and you should hear from @eileencodes (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

[kaspth]

❤️