docs: reword and improve the support message

[meenbeese]

This is based on feedback from a constructive comment I saw on Hacker News:

I hope musicians can pay bills with likes, since ponying up €10.99 is a huge ask. Key changes made:

• We realistically won't convince anyone to buy Spotify Premium if they are using a free music client
  
• Mention better options like buying merch, albums, tickets instead of superficial engagement ideas
  
• I also improved and shortened the wording a bit as it was too long and hard to read before