Update 'Reference'

Reference.md

@@ -45,3 +45,67 @@ The currently available opcodes are as follows:
     - `<filename>[-optional-list-of-functions-or-variables-to-import]`
     - the list of values should be separated by a `-`. Each value should have the following syntax:
     - `<f or v, function or variable, respectively><name of function/variable>`
+
+
+
+# Comments
+
+You can use a `#` character to create a comment. It works anywhere in the line, but everything after the `#` will be ignored by the interpreter.
+
+For example:
+
+```sandwich
+pHello World!
+
+# This line will be ignored
+
+pThis part will be printed # and this part will not be printed
+```
+
+
+# Example Program
+
+Here's an example program that shows all of these concepts in action:
+
+```sandwich
+lhHello
+lwWorld!
+# prints hello world
+p$h $w
+p$h $w
+lx33333333
+ly3
+a15-16
+s19-4
+m3-3
+d9-$y
+a$x-27
+lv0
+fza$v-2
+lv*z
+p$v
+
+fxa3-3
+fys*x-1
+p*y
+
+fxa10-10
+fys10-5
+p*x *y
+
+ptest # Prints test
+
+itest.txt-vf-fc
+#itest.txt
+p$f
+p*c
+
+ln<Enter your name: 
+pYour name is $n.
+
+lo<Enter the first number: 
+lt<Enter the second number: 
+
+faa$o-$t
+pThe result is *a
+```