update project structure

leetcode_py/28.py

@@ -0,0 +1,12 @@
+"""
+Given two strings needle and haystack, 
+return the index of the first occurrence of needle in haystack, 
+or -1 if needle is not part of haystack.
+"""
+class Solution:
+    def strStr(self, haystack: str, needle: str) -> int:
+        if needle in haystack:
+            return haystack.find(needle)
+        else:
+            return -1
+