add components tutorial to toc

Author: mcflugen

lessons/landlab/landlab/00_welcome.ipynb

@@ -45,6 +45,8 @@
     "  * Calculations on a grid elements\n",
     "  * Example: Fault scarp\n",
     "\n",
+    "* [Components](05-components.ipynb)\n",
+    "    * Example: Fault scarp with LinearDiffuser\n",
     "\n",
     "## More examples\n",
     "   \n",