Update Service Keys in ENSIP-5

[MidnightLightning]

In the "Service Keys" section of ENSIP-5, there's several examples given. However, as time marches on, the examples are a little less relevant than when they were created. Notably, Peepeth appears to have shut down (seems last time website was accessible was January 2024, though I can find no closure announcement), and there are several other social media sites that ENS users are likely more familiar with. Therefore, I'd recommend evaluating if the following changes should be done to that section:

• Remove com.peepeth as an example
• Add in new examples:
  • Fediverse/Mastodon as a platform doesn't have a single domain for users to have their profile on. This one behaves more like an email, so possibly it needs a text key of fediverse (behaving similarly to email)
  • Warpcast: com.warpcast
  • Threads: net.threads
• Update com.twitter to be com.x? Twitter officially changed its logo to "X", and x.com as a domain redirects to them, so should that be the canonical service link for that social media site?