update featured challenges

add 188-voice-chatbot to featured challenges

Author: kfahn22

content/pages/homepage/index.json

@@ -33,7 +33,7 @@
     "featured": [
       "c1-maurer-rose",
       "171-wave-function-collapse",
-      "187-bayesian-text-classification",
+      "188-voice-chatbot",
       "116-lissajous-curve-table",
       "108-barnsley-fern",
       "31-flappy-bird"