Fix formatting of markup in the docs for WP_HTML_Tag_Processor

[johnbillion]

Trac ticket: https://core.trac.wordpress.org/ticket/57840

There's many helpful code examples in the docs for the WP_HTML_Tag_Processor class but they're all indented by four unnecessary spaces. They use the ```php wrapper which makes the indentation appear in the code blocks on the developer reference site. This fixes that by removing the extraneous indentation.

There's also an additional fix for the note about the U+FFFD character.

Example URLs that display the unnecessary indentation:

• https://developer.wordpress.org/reference/classes/WP_HTML_Tag_Processor/
• https://developer.wordpress.org/reference/classes/WP_HTML_Tag_Processor/is_tag_closer/

[adamziel]

Looking great, thanks! Also cc @dmsnell

[johnbillion]

https://core.trac.wordpress.org/changeset/55718

[dmsnell]

Thanks @johnbillion - I was under the impression the indentation was required, but I've double-checked after this change and the code still renders as code at least in PHPStorm and VSCode.

[dmsnell]

@johnbillion what was wrong with the U+FFFD note?
looks right to me in the linked documentation, which I think is still reflecting the code before this change

[johnbillion]

I was under the impression the indentation was required

Yeah you just need either the backticks or the indentation but not both 😄

what was wrong with the U+FFFD note?

It was just to remove the unprintable character from the source code 👍

looks right to me in the linked documentation

Yeah the docs on the developer reference site only get regenerated from the source when each new version of WordPress is released

[dmsnell]

but not both

ahaa

It was just to remove the unprintable character from the source code 👍

that character is printable though, and it printed

maybe it's confusing because that character is the character used when the string has invalid characters in it?

I think maybe it was a mistake to remove. we added that originally to show what it is, thinking people would more readily recognize � than U+FFFD

[johnbillion]

Ohhhh that is the actual unicode character displayed as a replacement when a character is unprintable? I see.

[dmsnell]

@johnbillion do you have any thoughts about me adding it back in? maybe surround it in quotes this time to try and make it more obvious that it's the actual character?

sorry this wasn't caught in review. I would have noted it, but the PR was created and merged while I was still asleep