Update issue templates (#792)

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -0,0 +1,14 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+If you're already a Box customer, please send an email preview-team@box.com with your admin's information/enterprise ID.