Site Health: Revise strings in dashboard widget

[dlh]

The attached patch offers some suggestions for improving the strings in wp_dashboard_site_health().

Because the new widget is going to be prominent for many users when WordPress 5.4 releases, I would offer that the strings should get another pass so that the new release makes a great first impression. My suggestions are just suggestions, and I'd love to hear from others as well.

Here are the strings changed in the patch with some background on the rationale:

No Site Health information has been gathered yet, you can do so by visiting the Site Health screen, alternatively the checks will run periodically.

• This sentence can be reworked to avoid comma splices.
• It might not be clear to a user that "the checks" is what gathers "site health information."

<a href="%s">Visit the Site Health screen</a> to gather information on about your site.

• on about is a typo.
• This string contains the same call-to-action as the previous string, but it includes a link. Merging the two strings might simplify the message in the widget.

Your site has critical issues that should be addressed as soon as possible to improve the performance or security of your website.

• It might puzzle a user that WordPress would know that there are critical issues but not know whether they were related to performance or security. Since critical issues arguably affect both, security and performance might be more accurate, and, moreover, consistent with the string below it.
• "your website" isn't necessary given the existing reference to "Your site."

Your site health is looking quite good, but there are still some things you can do to improve the performance and security of your website.

• The string in site-health.js is just "looking good," and, to me, that gets the point across.
• "your website" can be made unnecessary by using "Your site's health."

Take a look at the <strong>%1$d items</strong> on the <a href="%2$s">Site Health Status screen</a>.

• It's not clear to me why this string wouldn't use _n().
• This is the only time in the widget it's called the "Site Health Status screen."