fix recent typos causing invalid JSON

recent commit (dfc565c) edited Chapter 1,
introducing typos and making it invalid JSON. This fixes those typos.

Author: minrk

Chapter1_Introduction/Chapter1_Introduction.ipynb

@@ -838,7 +838,7 @@
      "source": [
       "### Interpretation\n",
       "\n",
-      "Recall that Bayesian methodology returns a *distribution*. Hence we now have distributions to describe the unknown $\lambda$s and $\\tau$. What have we gained? Immediately, we can see the uncertainty in our estimates: the wider the distribution, the less certain our posterior belief should be. We can also see what the plausible values for the parameters are: $\\lambda_1$ is around 18 and $\\lambda_2$ is around 23. The posterior distributions of the two $\\\\lambda$s are clearly distinct, indicating that it is indeed likely that there was a change in the user's text-message behaviour.\n",
+      "Recall that Bayesian methodology returns a *distribution*. Hence we now have distributions to describe the unknown $\\lambda$s and $\\tau$. What have we gained? Immediately, we can see the uncertainty in our estimates: the wider the distribution, the less certain our posterior belief should be. We can also see what the plausible values for the parameters are: $\\lambda_1$ is around 18 and $\\lambda_2$ is around 23. The posterior distributions of the two $\\lambda$s are clearly distinct, indicating that it is indeed likely that there was a change in the user's text-message behaviour.\n",
       "\n",
       "What other observations can you make? If you look at the original data again, do these results seem reasonable? \n",
       "\n",