Redirect "Questions" issue option to Discussions (#16443)

This PR removes the "Question" issue template, and adds a section to the
issue creation menu labeled "Question" which redirects to a new Q&A
discussion post.

I have this set up on my fork if you want to see what it looks like:
https://github.com/132ikl/nushell/issues/new/choose

## Release notes summary - What our users need to know
N/A

## Tasks after submitting
- [ ] Convert all issues currently tagged with the "question" label into
Discussions

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Question
+    url: https://github.com/nushell/nushell/discussions/new?category=q-a
+    about: Create a new Q&A discussion post

.github/ISSUE_TEMPLATE/question.yml

@@ -1,21 +0,0 @@
-name: Question
-description: "When you have a question to ask"
-labels: "question"
-body:
-  - type: textarea
-    id: problem
-    attributes:
-      label: Question
-      description: Leave your question here
-      placeholder: |
-        A clear and concise question
-        Example: Is there any equivalent of bash's $CDPATH in Nu?
-    validations:
-      required: true
-  - type: textarea
-    id: context
-    attributes:
-      label: Additional context and details
-      description: Add any other context, screenshots or other media that will help us understand your question here, if needed.
-    validations:
-      required: false