General: Add Learn WordPress links to admin Help panel and default comment

[Infinite-Null]

Trac ticket: #62510

Description

This PR adds Learn WordPress links to improve resource discoverability in two locations:

1. The wp-admin Help panel
2. The default comment text

Why

• Helps users discover official WordPress learning resources more easily
• Provides direct access to learning materials from within wp-admin

Screenshot:

[github-actions]

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Core Committers: Use this line as a base for the props when committing in SVN:

Props ankitkumarshah, kaitohm.

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[github-actions]

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Test this pull request with WordPress Playground.

[kaitohm]

I think we should split this out onto a new line and add a little more context to the link.

Suggested change

	Commenter avatars come from <a href="%1$s">Gravatar</a>. Click here to <a href="%2$s">Learn WordPress</a>.'
	Commenter avatars come from <a href="%1$s">Gravatar</a>.
	If you're new to WordPress, check at these free <a href="%2$s">online courses at Learn WordPress</a>.'

[kaitohm]

This will direct users to specific courses relevant to them.

Suggested change

	esc_url( __( 'https://learn.wordpress.org/' ) )
	esc_url( __( 'https://learn.wordpress.org/learning-pathway/user/' ) )

[kaitohm]

I've updated the link and wording in the default comment to direct users specifically to online courses on Learn.

[Infinite-Null]

Hi @kaitohm,
I have made the changes requested please have a look at it at your convenience.
Thank you!

[kaitohm]

The front end changes look great and are what the Training Team were looking for. Thanks!