Add Supercraft to supported hosting providers

[supercraft-host]

Adds Supercraft (https://supercraft.host/) to the support list in src/data/providers.ts, with the matching key in i18n/en/code.json, in alphabetical order after STIPE per CONTRIBUTING.md.

[SleepyPopp]

Please follow our AI policy: https://github.com/GeyserMC/.github/blob/master/AI_POLICY.md

[supercraft-host]

Sorry, I missed the AI policy. Being transparent: I used Claude Code to draft
the wiki page this entry links to and the wording of this PR. The change itself
is two lines of data, and I can explain it: on our servers the Java port also
carries Minecraft's query listener on UDP and the next port is RCON, so Geyser
has to bind server port + 2. Neither 19132 nor the server port works on shared
nodes.

It was tested before opening, not just written: Geyser-Spigot 2.11.2 and
Floodgate 2.2.5 on a Paper server, both plugins loading, and a RakNet
unconnected ping from outside the machine answered with the server MOTD.

Happy to reword the entry or drop it if you would rather not carry it.