Notes about caching pages with a CSRF Form

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | no
| Applies to    | all
| Fixed tickets | #1216
This should be dashes `-----` (same for the other header)

Also, I think the capitalization should be (and slight reword):

`Why Varnish does not Cache these Pages by Default`