Update user template

Author: akclace

.github/ISSUE_TEMPLATE/3_testimonial.yml

@@ -1,6 +1,6 @@
-name: "Add a user/testimonial"
+name: "Add a user testimonial"
 description: Share how you use OpenRun project and grant permission to list your company.
-title: "User/Testimonial: <Company Name>"
+title: "User Testimonial: <Company Name>"
 labels: ["testimonial"]
 body:
   - type: input