add: minilibc to the examples

examples/minilibc/strlen.pasm

@@ -0,0 +1,18 @@
+; strlen
+
+set str "hello, world !\0"
+
+end_:
+mov eax, a2
+end
+
+main:
+mov a1, str 
+mov a2, 0
+
+loop:
+cmp (char)*a1, 0
+je end_
+add a2, 1
+add a1, 1
+jmp loop