Add TODO about CDTEXTFILE support.

README

@@ -42,6 +42,7 @@ Bugs/Todo
 * (toc) Only a single data file is supported.
 * (cue) CDTEXTFILE (a CDRWIN extension) is not recognized.
 * (cue) track_mode does not match cdrtools and CDRWIN docs.
+* (cue) Handle CDTEXTFILE for binary CD-TEXT.
 
 License
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