Create garryavx.md (#253)

* garryavx signed cla

contributors/garryavx.md

@@ -0,0 +1,11 @@
+2022-01-21
+
+I hereby agree to the terms of the Contributors License
+
+I furthermore declare that I am authorized and able to make this
+agreement and sign this declaration.
+
+Signed,
+
+Garry DeWitt
+https://github.com/garryavx