docs: Add notes for troubleshooting parsing errors

wiki/troubleshooting.md

@@ -0,0 +1,11 @@
+#### Troubleshooting parsing errors
+
+1. Open civ5save-editor locally or the [deployed version](https://bmaupin.github.io/civ5save-editor/)
+
+1. Open the browser dev tools (F12) and set it to pause on exceptions, including caught exceptions
+
+1. Open the problematic save file
+
+1. In the debugger select `_getProperties` to inspect the property name, byte offset, and values for previous properties
+
+1. Using the [property definitions](https://github.com/bmaupin/js-civ5save/blob/master/src/Civ5SavePropertyDefinitions.js) as a guide, go through the save file to determine where the incorrect byte offset may be