Java21 - Updating Downloads and Versions

[TacoGS]

This updates the version requirements in Using-the-right-Java.md to match modern version of Minecraft.

Additional Changes:

• This also changes the download for most Operations System options to Eclipse Temurin. The old ones got shifted to Other Distributiuons.
• This also changes locations of some descriptions to prevent critical information being presented later instead of earlier (Warning about M1/M2/M3 Macs for instance).
• This also changes formatting to make the page easier to read and not a continuous block of text.
• Slight change to _footer.md to update the copyright.