Clarify in our documentation that our shortcode analysis filter does not work in the block editor.

[rmarcano]

Please give us a description of the issue

We have documentation here on how to get Yoast SEO to analyze content inside shortcodes:
https://developer.yoast.com/customization/yoast-seo/filters/shortcodes-filter/

However, this only works in the Classic editor, not on the block editor.

We've received a support request from a user that was trying to use the filter without success.

We should add a comment in the documentation that this filter will only work in the Classic editor.

Additional information:

• Analysis in block editor should parse shortcodes and custom blocks wordpress-seo#16207
• Slack conversation here.