add github template from symfony (#289)

add github template from symfony

Author: ElectricMaxxx

.github/PULL_REQUEST_TEMPLAE.md

@@ -0,0 +1,10 @@
+| Q             | A
+| ------------- | ---
+| Branch?       | "master" for new features / the branch of the current release for fixes
+| Bug fix?      | yes/no
+| New feature?  | yes/no
+| BC breaks?    | yes/no
+| Deprecations? | yes/no
+| Fixed tickets | comma-separated list of tickets fixed by the PR, if any
+| License       | MIT
+| Doc PR        | reference to the documentation PR, if any