Create post-an-open-role.md (#658)

Added a new issue template to post recruitment to open roles

.github/ISSUE_TEMPLATE/post-an-open-role.md

@@ -0,0 +1,11 @@
+---
+name: Post an open role
+about: Recruit volunteers for specific open roles template
+title: 'LP: Open Role for: [Replace with NAME OF ROLE]'
+labels: 'complexity: Small, feature: recruitment/onboarding, missing: role, missing: milestone'
+assignees: ''
+
+---
+
+![image](https://user-images.githubusercontent.com/37763229/162591479-67a96690-854b-40c2-92e9-735b2bbe09b8.png)
+[INSERT DRAFT FROM THE Recruit volunteers for team open roles issue]