add several TODO comments

self-note: check this one after you come back!

src/gui/sampleEdit.cpp

@@ -28,6 +28,12 @@
 #include "sampleUtil.h"
 #include "util.h"
 
+// TODO:
+// - resample should change C-4 note
+// - clicking on waveform should give this window focus
+// - add "create instrument using this sample" option
+// - .dmc loading
+// - duplicate sample
 void FurnaceGUI::drawSampleEdit() {
   if (nextWindow==GUI_WINDOW_SAMPLE_EDIT) {
     sampleEditOpen=true;