Add some pseudocode to examples

examples/example1.S

@@ -1,4 +1,15 @@
 ; Evaluate 2*3+5
+;
+; pseudocode:
+; sum(prd(2, 3), 5)
+;
+; sum(a, b) {
+;   return a+b
+; }
+;
+; prd(a, b) {
+;   return a*b;
+; }
 
 main: push 2
       push 3

examples/example2.S

@@ -1,4 +1,10 @@
 ; I/O example - simple echo
+;
+; pseudocode:
+; do {                 // read
+;   x = in()
+;   out(x)
+; while(x - 0x0A != 0)
 
 read:  in
        dup

examples/example3.S

@@ -1,7 +1,23 @@
 ; Evaluate 2^10 - loop variant
+;
+; pseudocode
+; pow(2, 10)
+;
+; pow(base, exp) {
+;   acc = 1
+;
+;   do {                   // .loop
+;     if (exp == 0) {
+;       return acc         // .done
+;     }
+;
+;     acc = acc * base
+;     exp = exp - 1
+;   } while(true)
+; }
 
-push 2
-push 10
+push 2    ; base
+push 10   ; exp
 call &pow
 clr 2
 halt

examples/example4.S

@@ -1,4 +1,15 @@
 ; Evaluate 2^10 - recursive variant
+;
+; pseudocode:
+; pow(2, 10)
+;
+; pow(base, exp) {
+;   if (exp == 0) {
+;     return 1                        // .edge
+;   }
+;
+;   return base * pow(base, exp - 1)
+; }
 
 push 2          ; base
 push 10         ; exp

examples/example5.S

@@ -1,4 +1,17 @@
 ; The N-th element of Fibbonaci sequence - recursive variant
+;
+; pseudocode:
+; fibb(n) {
+;   if (n == 0) {
+;     return 1                    // .done0
+;   }
+;
+;   if ((n-1) == 0) {
+;     return 1                    // .done1
+;   }
+;
+;   return fibb(n-2) + fibb(n-1)
+; }
 
 push 6
 call &fibb