Reference Visual Content Considerations in avatar upload

[Userlog2]

When someone tries to change their avatar, they get this text next to the upload button:

Since the rules for images are specifically described at the Visual Content Considerations article, the text and link should be changed to the following:
"Please ensure your avatar adheres to the Visual Content Considerations.
This means it must be suitable for all ages, i.e. no nudity, offensive or suggestive content."
("profanity" -> "offensive" because profanity in user avatars is permitted.)