Adding Updating CODEOWNERS with ECCN as per Export Control Compliance (…

…#223)

* Updated/Added CODEOWNERS with ECCN
* Update CODEOWNERS

Remove reference to 'GUS'

Co-authored-by: Andrew Waterman <65307+awaterma@users.noreply.github.com>
Co-authored-by: Will Harney <62956339+wjhsf@users.noreply.github.com>

CODEOWNERS

@@ -0,0 +1,2 @@
+# Comment line immediately above ownership line is reserved for related information. Please be careful while editing.
+#ECCN:Open Source