Fix wrong parameter reference in Blackboard documentation #181

Job	Run time
🧪 Unit tests	3m 40s
cache-env	1s
🐧 Linux / Editor (x86_64, release)	13m 55s
🍎 macOS / Editor (x86_64, release)	6m 59s
🐧 Linux / Template (x86_64, release)	10m 17s
🔌 GDExtension / 🐧 Linux (x86_64, release)	42s
🍎 macOS / Editor (arm64, release)	5m 30s
🪟 Windows / Editor (x86_64, release)	8m 16s
🔌 GDExtension / 🐧 Linux (x86_64, debug)	1m 46s
🪟 Windows / Editor .NET (x86_64, release)	11m 48s
🔌 GDExtension / 🪟 Windows (x86_64, release)	1m 54s
🔌 GDExtension / 🪟 Windows (x86_64, debug)	2m 21s
🔌 GDExtension / 🍎 macOS (universal, release)	50s
🔌 GDExtension / 🍎 macOS (universal, debug)	52s
🍎 macOS / Make macOS Bundles	1m 18s
	1h 10m 9s

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