Simplify issue template

Author: novemberborn

.github/ISSUE_TEMPLATE/config.yml

@@ -1,8 +1 @@
 blank_issues_enabled: true
-contact_links:
-  - name: AVA on Spectrum
-    url: https://spectrum.chat/ava
-    about: Ask questions and discuss in our Spectrum community
-  - name: Stack Overflow
-    url: https://stackoverflow.com/questions/tagged/ava
-    about: Tag your question on Stack Overflow