Added Geyser Extensions loader (#6)

Modrinth just added a new loader type `geyser` for Geyser Extension.

Author: zefir-git

src/libmodpm/inventory/Config.d

@@ -52,6 +52,7 @@ public final class Config {
         FABRIC = "fabric",
         FOLIA = "folia",
         FORGE = "forge",
+        GEYSER = "geyser",
         IRIS = "iris",
         JAVA_AGENT = "java-agent",
         LEGACY_FABRIC = "legacy-fabric",
@@ -116,6 +117,7 @@ public final class Config {
             Loader.BUKKIT,
             Loader.BUNGEECORD,
             Loader.FOLIA,
+            Loader.GEYSER,
             Loader.PAPER,
             Loader.PURPUR,
             Loader.SPIGOT,