Simplify comments to be more concise and student-like

- Removed verbose explanations
- Made comments shorter and more casual
- Focus on key concepts rather than formal descriptions

01/Mux.hdl

@@ -11,7 +11,7 @@ CHIP Mux {
     OUT out;
 
     PARTS:
-    // Mux(a,b,sel) = Or(And(a, Not(sel)), And(b, sel))
+    // sel=0 picks a, sel=1 picks b
     Not(in=sel, out=tmp1);
     And(a=a, b=tmp1, out=tmp2);
     And(a=b, b=sel, out=tmp3);