Update bug and feature request templates.

Wording changes to try and push general questions onto discourse and
keep github issues/PRs for development. This makes bug and feature
request text point to "below" which has a General Question category
as present on discourse. Also changes the bug report template to ask
for a self contained reproducer with a simple definition of what that
is.

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -1,6 +1,6 @@
 ---
 name: Bug Report
-about: Create a report to help us improve Numba
+about: Report a bug. Not for asking general questions - see below.
 
 ---
 
@@ -23,8 +23,8 @@ Before submitting a bug report please ensure that you can check off these boxes:
 
 - [ ] I have tried using the latest released version of Numba (most recent is
  visible in the change log (https://github.com/numba/numba/blob/master/CHANGE_LOG).
-- [ ] I have included below a minimal working reproducer (if you are unsure how
- to write one see http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports).
+- [ ] I have included a self contained code sample to reproduce the problem.
+  i.e. it's possible to run as 'python bug.py'.
 
 <!--
 

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -1,6 +1,8 @@
 ---
 name: Feature Request
-about: Tell us about something in the Python language/NumPy you'd like Numba to support.
+about: Tell us about something in the Python language/NumPy you'd like Numba to support. Not for asking general questions - see below.
+
+---
 
 ---
 

.github/ISSUE_TEMPLATE/config.yml

@@ -2,7 +2,7 @@ blank_issues_enabled: false
 contact_links:
   - name: General Question
     url: https://numba.discourse.group/c/numba/community-support/
-    about: "If you have a question like *How do I speed up X?* then please ask on Numba's discourse instance."
+    about: "If you have a general question (not a bug report or feature request) then please ask on Numba's discourse instance."
   - name: Quick Question/Just want to say Hi!
     url: https://gitter.im/numba/numba
     about: "If you have a quick question or want chat to users/developers in real time then please use gitter.im/numba/numba"