Comment out *.dot pattern with note, based on reviewer suggestion

Author: RScrafted

Terraform.gitignore

@@ -36,8 +36,8 @@ override.tf.json
 .terraformrc
 terraform.rc
 
-# Ignore graph files
-*.dot
+# Optional: ignore graph output files generated by `terraform graph`
+# *.dot
 
 # Optional: ignore plan files saved before destroying Terraform configuration
 # Uncomment the line below if you want to ignore planout files.