Update jsdoc.config.json

Exclude lib directory.

utils/docs/jsdoc.config.json

@@ -16,6 +16,7 @@
             "src"
         ],
         "exclude": [
+            "src/extras/lib",
             "src/renderers/common/extras/PMREMGenerator.js",
             "examples/jsm/helpers/LightProbeHelperGPU.js",
             "examples/jsm/helpers/TextureHelperGPU.js",