fix dead link to the projects "homepage"

Getting to the notebook via the main page at https://nbviewer.jupyter.org/ shows the notebook with a 'homepage' link, clicking on it gives a 404 error.

Author: basnijholt

Chapter1_Introduction/Ch1_Introduction_PyMC3.ipynb

@@ -17,7 +17,7 @@
     "___\n",
     "\n",
     "\n",
-    "Welcome to *Bayesian Methods for Hackers*. The full Github repository is available at [github/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers](https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers). The other chapters can be found on the project's [homepage](g). We hope you enjoy the book, and we encourage any contributions!"
+    "Welcome to *Bayesian Methods for Hackers*. The full Github repository is available at [github/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers](https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers). The other chapters can be found on the project's [homepage](https://camdavidsonpilon.github.io/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers/). We hope you enjoy the book, and we encourage any contributions!"
    ]
   },
   {