Fix rules-to-wiki and generalize some code for extension's equivalents (#696)

* Fix rules-to-wiki output

* Publicize OLD_OUT in RulePrinter to simplify extension's equivalents

And rename to CarpetRulePrinter because of the same reason

src/main/java/carpet/utils/CarpetRulePrinter.java

@@ -0,0 +1,33 @@
+package carpet.utils;
+
+import carpet.CarpetServer;
+import net.fabricmc.api.DedicatedServerModInitializer;
+import net.fabricmc.loader.api.entrypoint.PreLaunchEntrypoint;
+
+import java.io.PrintStream;
+import java.lang.System;
+
+/**
+ * Runs only from GitHub Actions to generate the wiki
+ * page with all Carpet rules on it.
+ * It is here so it can be managed by the IDE
+ *
+ */
+public class CarpetRulePrinter implements DedicatedServerModInitializer, PreLaunchEntrypoint {
+    public static final PrintStream OLD_OUT = System.out;
+
+    @Override
+    public void onInitializeServer() {
+        // Minecraft (or whatever) changes the System.out to have prefixes,
+    	// our simple parser doesn't like that. So we change it back
+        System.setOut(OLD_OUT);
+        CarpetServer.onGameStarted();
+        CarpetServer.settingsManager.printAllRulesToLog(null);
+        System.exit(0);
+    }
+    
+    @Override
+    public void onPreLaunch() {
+        // Just initializes our OLD_OUT by nooping the class
+    }
+}