freadln.c: add new TODOs

c-programming/io/freadln.c

@@ -8,6 +8,10 @@
  * License: Creative Commons Zero 1.0 Universal
  *
  * TODO: Figure out potential problems
+ * TODO: Add 'flushing' of STDIN (while there are characters, read them) before
+ * the input reading loop to avoid input queues
+ * TODO: Add the feature of reading from arbitrary file, then extract a macro:
+ * `#define finreadln(output, length_out) freadln(stdin, output, length_out)`
  */
 
 #include "freadln.h"