Update const_DOUBLE_PI

src/basic/math_consts/e2e5.const_DOUBLE_PI.s

@@ -2,8 +2,13 @@
 ;; #LAYOUT# *   BASIC_0 #TAKE
 ;; #LAYOUT# *   *       #IGNORE
 
+; This file is under the MIT license, it contains code released by Microsoft Corporation.
+; See LICENSE for more information.
+
+; Math package - 2 * pi
+;
+; This is verified to be identical to the original Microsoft implementation where it was named TWOPI.
 ;
-; Math package - a constant, for documentation see:
 ; - https://sourceforge.net/p/acme-crossass/code-0/38/tree/trunk/ACME_Lib/cbm/c64/float.a?force=True
 ;