[Update] Approve "Preferred Scene Titles"

[AdultSun]

Needs official approval: https://guidelines.stashdb.org/docs/scenes/scene-titles/#preferred-scene-titles

This one does not mention any exceptions to the guideline, even though the section immediately below lists all of the relevant exceptions. We should probably include something like, "See the next section for possible exceptions."

Also, this one was written following the prevailing consensus that original data is more valuable on StashDB than current data. The reasoning here is that original data is unchanging but can be hard to find while current data is a moving target but is usually easy to re-scrape.