Update TODO.md

Author: leonelsanchesdasilva

TODO.md

@@ -2,8 +2,7 @@ XSLT-processor TODO
 =====
 
 * Rethink match algorithm, as described in https://github.com/DesignLiquido/xslt-processor/pull/62#issuecomment-1636684453;
-* Deal with namespaces (if namespaces are not the same in XSLT and XML document, matches do no occur.)
-* XSLT validation
+* XSLT validation, besides the version number;
 * XSL:number
 * `attribute-set`, `decimal-format`, etc. (check `src/xslt.ts`)