Update pull_request_template.md

update pr template to link to new config requirement page on betaflight.com

.github/pull_request_template.md

@@ -1,4 +1,5 @@
 ## Pull-Request requirements
 - Adhere to https://betaflight.com/docs/development/manufacturer/requirements-for-submission-of-targets.
+  AND https://betaflight.com/docs/development/manufacturer/config-target-guidance
 - Pull-Request only from a custom branch, not `master`.
 - Replace this text with details of your own.