Update issue templates

Author: joachimweyl

.github/ISSUE_TEMPLATE/custom.md

@@ -0,0 +1,19 @@
+---
+name: Custom issue template
+about: Describe this issue template's purpose here.
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+## Motivation
+
+## Completion Criteria
+
+## Description
+- [ ] 
+
+## Completion dates
+Desired - YYYY-MM-DD
+Required - TBD