Fix documentation: correct JVM memory floor values (1024M/2048M) (#64)

* Initial plan

* docs: fix JVM memory floor values in README (1024M/2048M)

Co-authored-by: TimInTech <129355283+TimInTech@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: TimInTech <129355283+TimInTech@users.noreply.github.com>

Author: Copilot

README.md

@@ -166,7 +166,7 @@ crontab -e
 ### JVM memory (Java)
 
 
-The installer sets `Xms ≈ RAM/4` and `Xmx ≈ RAM/2` with floors `256M/448M` and an `Xmx` cap of `≤16G`. Override in `/opt/minecraft/start.sh`.
+The installer sets `Xms ≈ RAM/4` and `Xmx ≈ RAM/2` with floors `1024M/2048M` and an `Xmx` cap of `≤16G`. Override in `/opt/minecraft/start.sh`.
 
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