SVI Add ch07

doc/part01/ch07.md

@@ -10,8 +10,8 @@ iterator `..<`(a, b: int): int = # 1
    while i < b:
      yield i                     # 2
      inc i                       # 3
-  iterator items(s: seq[Point]): Point =
-    for i in 0 ..< s.len:        # 4
+iterator items(s: seq[Point]): Point =
+   for i in 0 ..< s.len:        # 4
       yield s[i]
 ```