fix: make function doc examples runnable standalone #80

Job	Run time
Build extension binaries / Generate matrix	10s
Build extension binaries / linux_arm64	5m 8s
Build extension binaries / linux_amd64	6m 6s
Build extension binaries / windows_amd64	17m 12s
Build extension binaries / osx_amd64	2m 33s
Build extension binaries / wasm_mvp	5m 39s
Build extension binaries / osx_arm64	3m 1s
Build extension binaries / windows_amd64_mingw	17m 54s
Build extension binaries / wasm_threads	5m 39s
Build extension binaries / wasm_eh	5m 44s
	1h 9m 6s

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