Improve design of "Upgrading PHP" support page

[flixos90]

With #2996, we created a first iteration of the "Upgrading PHP" information page and got it up on wordpress.org. This version is in a good state regarding content, however it never received proper design - the content was simply put on a page.

We'd like to have an improved design for this page, and also allow the page to have a dynamic header, depending on a php_version GET parameter that can be passed in the URL. If that parameter is passed and contains a PHP version that is considered outdated, a warning message can be shown and simulate better context, for example when WordPress core links to the page because of an outdated version detected. If no such parameter is passed, nothing will be shown, like it is at the moment.

There's an initial mockup for a design that @jaymanpandya created a while ago, which I'll upload as attachment to this ticket.

Here's the next steps we envision for this:

1. Get feedback on the mockup from the design team, with emphasis on how this could be integrated with the general make.wordpress.org design.
2. Get feedback from the meta team in terms of how freely we can work on the design, as it should probably still be coherent with the general design of make.wordpress.org support pages.
3. Implement the dynamic page header using a php_version GET parameter as a simple shortcode, or alternatively Gutenberg block.
4. Implement the design agreed on for both the static page content and the dynamic header.

[flixos90]

initial "Upgrading PHP" page design mockup

[flixos90]

Notes on the above mockup (props @jaymanpandya for it):

• We'll need to iterate to get a design that fits into make.wordpress.org/support/.
• The sharing icons and the contextual bar at the top are not really necessary.
• The scroll-to-top button may be useful, but is also optional, if it requires too many technical changes.

[Clorith]

Drop by #docs, this seems like something that should be discussed alongside the HelpHub project which also includes a bit of designs for the support theme for standalone pages, and already has design team members on board.

[obenland]

@Clorith @flixos90 Any updates here?

[Clorith]

@alexdenning and @jaymanpandya will be looking at the design and make a plan for the page.

[ibdz]

We've discussed in ​Design triage today and agreed to close this ticket as the ​Update PHP page had already been in HelpHub's design template.