Sidebar: update post editor help links to use newer documentation

[arcangelini]

What?

There are two links to WordPress.org documentation that I believe could be better linked. I am proposing to change:

From	To
https://wordpress.org/support/article/excerpt/	https://wordpress.org/support/article/settings-sidebar/#excerpt
https://wordpress.org/support/article/writing-posts/#post-field-descriptions	https://wordpress.org/support/article/settings-sidebar/#permalink

Why?

Permalink

This link is currently a bit out of date as it pertains to the Classic editor. The article gives very few information to the user about the component they just clicked on. The link gives context to the exact element they clicked on and has links to more details if they want.

Excerpt

While the link is relevant in general and up-to-date, the new link provides a better summary and is within the context of the element they just clicked. This new article also has links to the previous one in case the user wants more details.

How?

Manually change the URL for each component.

Testing Instructions

1. Go to the editor
2. In the sidebar click the help links
3. You should go to the new articles

Screenshots or screencast

[github-actions]

👋 Thanks for your first Pull Request and for helping build the future of Gutenberg and WordPress, @arcangelini! In case you missed it, we'd love to have you join us in our Slack community, where we hold regularly weekly meetings open to anyone to coordinate with each other.

If you want to learn more about WordPress development in general, check out the Core Handbook full of helpful information.

[talldan]

Thanks for doing this and congrats on your first contribution 🎉

[github-actions]

Congratulations on your first merged pull request, @arcangelini! We'd like to credit you for your contribution in the post announcing the next WordPress release, but we can't find a WordPress.org profile associated with your GitHub account. When you have a moment, visit the following URL and click "link your GitHub account" under "GitHub Username" to link your accounts:

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Kudos!