Move package xml before copyright

Having the same copyright on all files made the documentation script
to include it multiple times in the package information.

core/encoding/xml/tokenizer.odin

@@ -1,3 +1,5 @@
+package xml
+
 /*
 	An XML 1.0 / 1.1 parser
 
@@ -9,7 +11,7 @@
 	List of contributors:
 		Jeroen van Rijn: Initial implementation.
 */
-package xml
+
 
 import "core:fmt"
 import "core:unicode"
@@ -433,4 +435,4 @@ scan :: proc(t: ^Tokenizer) -> Token {
 		lit = string(t.src[offset : t.offset])
 	}
 	return Token{kind, lit, pos}
-}
+}