Clarify "No AI-generated songs" rule

[Hans5958]

• Page: rules/no-ai-generated-songs
• File: src/content/rules/no-ai-generated-songs.mdx

It is understandable that rule is subject to change, and the definite hate of Sora songs, but as I said on the Discord server, this rule needs clarifications such as...

1. Improve the clarity the prohibition (e.g. "songs that uses the AI-generated elements are not allowed" or "song entries for AI-generated songs and it's derivatives are not allowed")
2. Defining what constitute AI-generated songs clearer (limit to GenAI such as Suno, RVC? AI voicebanks such as Synth V and Vocaloid 6?)

This is so that those that are not versed with the situation (e.g. those that are unaware about CryDie situation or songs made by Sora) can be sure what is eligible and what isn't, without being bullied by seasoned members that have quite a dislike with them (e.g. "you should've known that XYZ is not eligible!".