chore: Added tech issue template (#560)

.github/ISSUE_TEMPLATE/tech-issue.md

@@ -0,0 +1,23 @@
+---
+name: Tech Issue
+about: Engineering-specific technical work that is not product-specific. Engineering team "owns" these issues.
+title: ""
+labels: tech
+assignees: ""
+---
+
+## Motivation
+
+Why is this work important to engineers?
+
+## Definition of Done
+
+What should the end result look like? What will have been changed?
+
+## Tasks
+
+Detail the specific tasks that can be used to accomplish the desired changes.
+If detailed steps cannot be provided at this time, please file a [Tech Proposal](https://docs.google.com/document/d/1o2vuvl-kXwRJN1nBoPzJS_MAQgDGYnjmPZWa4qRDi-I/edit#heading=h.7dvzhm7gqc3v) instead.
+
+- [ ]
+- [ ]