fix groups example, add comments

examples/core/src/main.leo

@@ -1,4 +1,7 @@
-// The 'core' main function.
+// This function takes as input a field `a` and calls several core circuit functions.
+// Core circuit functions are built-in to the Leo language and call handwritten, optimized circuits in the AVM.
+// To call a core circuit function, use the correct capitalized circuit identifier followed by two colons
+// and then the function. Example: `Pedersen64::hash()`.
 function main(a: field) -> field {
     let b: field = BHP256::hash(a);
     let c: field = Poseidon2::hash(b);

examples/groups/inputs/groups.in

@@ -1,3 +1,4 @@
 // The program input for groups/src/main.leo
+// Leo will use provided string as the x coordinate and attempt to recover the y coordinate to form a group.
 [main]
-a: group = (7810607721416582242904415504650443951498042435501746664987470571546413371306, 1867362672570137759132108893390349941423731440336755218616442213142473202417)group;
+a: group = 1817767092074430972953743941103352519057913259183777531581123188265134806220group;

examples/groups/src/main.leo

@@ -1,4 +1,5 @@
-// The 'groups' main function.
+// This function takes a group coordinate as input `a` and performs several operations which should output the `0group`.
+// Note that the operations can be called as associated functions on the `a` variable.
 function main(a: group) -> group {
     // unary
     let e: group = a.double(); // 2a