Remove .md and image files and move python files into main chapter folders

thinkcspy/Chapter-6-Exercises/problem13.py

@@ -0,0 +1,14 @@
+# Runestone.Academy thinkcspy course
+# Chapter 6
+# Problem 13
+
+def sumTo(n):
+    # your code here
+    runningTotal = 0
+    
+    for counter in range(n):
+        runningTotal = runningTotal + (n+1)/2
+        
+    return runningTotal
+
+print(sumTo(10))