Small updates to ML track for deployment

Author: dansbecker

learntools/machine_learning/kernels_metadata/ch2/kernel-metadata.json

@@ -1,4 +1,4 @@
-{"title": "Exercise: Exploring Your Data",
+{"title": "Exercise: Explore Your Data",
   "id": "dansbecker/exercise-exploring-your-data",
   "code_file": "../../nbs/ch2.ipynb",
   "language": "python",

learntools/machine_learning/kernels_metadata/ch3/kernel-metadata.json

@@ -1,5 +1,5 @@
-{"title": "Exercise: Building Your Model",
-  "id": "dansbecker/exercise-building-your-model",
+{"title": "Exercise: Your First Machine Learning Model",
+  "id": "dansbecker/exercise-build-your-first-model",
   "code_file": "../../nbs/ch3.ipynb",
   "language": "python",
   "kernel_type": "notebook",

learntools/machine_learning/kernels_metadata/tut2/kernel-metadata.json

@@ -1,5 +1,5 @@
-{"title": "Exploring Your Data",
-  "id": "dansbecker/exploring-your-data",
+{"title": "Explore Your Data",
+  "id": "dansbecker/explore-and-understand-your-data",
   "code_file": "../../nbs/tut2.ipynb",
   "language": "python",
   "kernel_type": "notebook",

learntools/machine_learning/kernels_metadata/tut3/kernel-metadata.json

@@ -1,5 +1,5 @@
-{"title": "Building Your Model",
-  "id": "dansbecker/building-your-model",
+{"title": "Your First Machine Learning Model",
+  "id": "dansbecker/your-first-machine-learning-model",
   "code_file": "../../nbs/tut3.ipynb",
   "language": "python",
   "kernel_type": "notebook",

learntools/machine_learning/kernels_metadata/tut5/kernel-metadata.json

@@ -1,5 +1,5 @@
 {"title": "Underfitting and Overfitting",
-  "id": "dansbecker/underfitting-and-overfitting",
+  "id": "dansbecker/underfitting-overfitting-and-model-optimization",
   "code_file": "../../nbs/tut5.ipynb",
   "language": "python",
   "kernel_type": "notebook",

learntools/machine_learning/nbs/ch2.ipynb

@@ -138,7 +138,7 @@
     "Check out this **[discussion thread](https://www.kaggle.com/learn-forum/60581)** to see what others think or to add your ideas.\n",
     "\n",
     "## Keep Going\n",
-    "Move on to **[Select and Filter Your Data](https://www.kaggle.com/dansbecker/selecting-and-filtering-in-pandas)** for closer examination and modeling.\n",
+    "Move on to **[Reviewing Your Data](https://www.kaggle.com/dansbecker/your-first-machine-learning-model)** for closer examination and modeling.\n",
     "\n",
     "---\n",
     "**[Course Home Page](https://www.kaggle.com/learn/machine-learning)**\n",