Update examples (MHKiT-Software#417)

This PR fixes a couple small issue with example notebooks:
- reruns the WEC-Sim power performance example so that it does not
include errors
- fixes typo in ADCP discharge example title

Author: akeeste

examples/adcp_disharge_example.ipynb renamed to examples/adcp_discharge_example.ipynb

@@ -4,7 +4,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# ADCP Disharge Example\n",
+    "# ADCP Discharge Example\n",
     "\n",
     "This example notebook overviews how to calculate discharge from an ADCP transect. The example data used in this notebook was taken by a Teledyne RDI RiverPro ADCP, an instrument purpose-built for calculating discharge from a survey transect, but the following workflow can be used with any ADCP's data, given that there is GPS information and/or bottom track measurements stored in the ADCP file.\n",
     "\n",