Correct typo

documents/references.md

@@ -13,7 +13,7 @@ This ended up being more complicated than I expected.
 * Main Ref was: <https://stackoverflow.com/a/51370419>
 * Secondary Ref: <https://math.stackexchange.com/questions/428843/draw-directional-arrows-on-a-given-line>
 
-### Trig "Cheat Sheet" to Help Determine Self-connecting Loop Coorinates
+### Trig "Cheat Sheet" to Help Determine Self-connecting Loop Coordinates
 * <http://tutorial.math.lamar.edu/pdf/trig_cheat_sheet.pdf>
 
 ### Using Plotly for "Network Graphs"