Remove the github-markdown class from lesson content

[aurooba]

Removing the github-markdown class brings back 16px font sizing on lesson content, which is far more accessible than 14px. Right now Lessons are harder to read than necessary because the body is using 14px. It also feels visually different from other parts of public-facing WordPress documentation.

Right now, removing that class also removes the borders underneath subheadings. If this is a style we should be keeping, please let me know so I can update this PR with an additional commit. :)

Before:

After:

[aurooba]

(Alternatively, we can modify the .github-markdown class itself to use font-size: 16px)

[hlashbrooke]

The paragraph font size looks good after this change, but the headings look bigger and much less neat. Could you update this PR t ensure the headings remain the same? Changing the font size for the github-markdown paragraphs would probably be easiest I think.

[aurooba]

Can do tomorrow, @hlashbrooke!

[jonathanbossenger]

@aurooba hey 👋

Are you still available to refresh this PR based on @hlashbrooke's suggestions?

[jonathanbossenger]

Personally, I don't see the problem with just removing the class

Before

After

I'm in favour of merging this as is, and we can always add the header border and change the fonts if it's a problem later.

[digitalchild]

I agree that removing this is better, as it makes it consistent with the rest of the site styles.

https://learn.wordpress.org/tutorial/create-block-theme-improvements/

You can see this on other pages on learn, the headings are slightly bigger and without the underline.

[costdev]

When removing the .github-markdown class, the following elements will be affected:

• Paragraph <p>
• Heading Level 1-6 <h1-h6>
• Blockquote <blockquote>
• Pre-formatted <pre>
• Horizontal Rule <hr>
• Table <table>
• Links <a>, Code <code> and Teletype <tt> inside Heading Level 1-6 <h1-h6>
• Ordered Lists <ol>, Unordered Lists <ul> and List Items <li>
• Description Lists <dl>, Description Terms <dt> and Description Details <dd>

When testing the PR, view several pages with differing content to get more insight into how removing this class will affect the appearance of existing content. Everyone may love the result, it's just best to know what the whole result is before committing to the change. 🙂

[jonathanbossenger]

I did a search for the use of the .github-markdown class across the rest of our content and pages, and could only find one other place it's in use, on the Course landing page.

Here is a screenshot with the class removed.

As you can see, there is a small visual bug in the module lesson list, which can be fixed by applying a font-size of 14px to the .wp-block-sensei-lms-course-outline .wp-block-sensei-lms-course-outline-module class selector, which is what the original github-markdown class does.