Add a question template

Since I want to remove the blank issue option, we need to provide a
template for questions.

Author: mhucka

.github/ISSUE_TEMPLATE/4-question.yml

@@ -0,0 +1,40 @@
+name: Question
+description: As a question
+type: Question
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thank you for your interest in qsim! Before continuing, it's worth
+        [searching through the existing issues in this
+        repository](https://github.com/quantumlib/qsim/issues?q=is%3Aissue) in
+        case the same question has already been asked and possibly answered.
+
+  - type: textarea
+    attributes:
+      label: What is the question?
+      description: >-
+        Please provide enough details and contextual information so that the
+        question is answerable.
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: Does this concern a specific version of qsim? If so, what version?
+      description: >-
+        If the question involves specific features or operation of
+        qsim/qsimcirq, please let us know the version number.
+    validations:
+      required: false
+
+  - type: input
+    attributes:
+      label: Is it specific to a computing environment? If so, which one?
+      description: >-
+        If the platform and operating system version may be relevant, please
+        tell us those details as well. It may matter, for example, whether you
+        are using Linux, macOS, Windows, or Google Colab, as well as whether
+        you are trying to use CUDA (and what version), and other details.
+    validations:
+      required: false