Fixing typo

Signed-off-by: Aryan Roy <aryanroy5678@gmail.com>

examples/intro/inducing_path.py

@@ -79,7 +79,7 @@
 # this returns False
 print(pywhy_graphs.inducing_path(G, "X1", "X3", L, S))
 
-# We need add X6, a collider on the path, to S
+# We need to add X6, a collider on the path, to S
 
 L = {"L1", "L2", "X3"}
 S = {"X6"}