add more examples

examples/dice.noug

@@ -1,4 +1,5 @@
-# dice
+# dice roll
+
 import random
 while True then
     var input_ = input("'exit' to exit, anything else to roll a dice: ")

examples/harmonic_mean.noug

@@ -0,0 +1,11 @@
+# harmonic mean between 2 numbers
+
+def mean(x, y) -> (x + y) / 2
+
+def harmonic_mean(x, y) -> 1 / mean(1/x, 1/y)
+
+print("Harmonic mean between two numbers")
+var x_ = input_int("Enter first number: ")
+var y_ = input_int("Enter second number: ")
+
+print(harmonic_mean(x_, y_))

examples/pyramid_volume.noug

@@ -0,0 +1,11 @@
+# calculate the volume of a pyramid
+
+def vol_pyramid(side, height)
+	var area = side ^ 2
+	return (1/3) * area * height
+end
+
+var side_ = input_int("Enter the side of the pyramid: ")
+var height_ = input_int("Enter the height of the pyramid: ")
+
+print(vol_pyramid(side_, height_))

examples/reverse_string.noug

@@ -0,0 +1,10 @@
+# reverse a string
+
+var string = input("Enter a string to reverse: ")
+var new_string = ''
+
+for letter in list(string) then
+	var new_string = letter + new_string
+end
+
+print(new_string)