deps: move typedoc to optionalDependencies so older node won't complain (hopefully)
deps: move typedoc to optionalDependencies so older node won't complain (hopefully)

royaltm/node-murmurhash-native,royaltm/node-murmurhash-native,royaltm/node-murmurhash-native,royaltm/node-murmurhash-native,royaltm/node-murmurhash-native,royaltm/node-murmurhash-native