github crash_report: Migrate template to YAML

.github/ISSUE_TEMPLATE/crash_report.md

@@ -1,15 +0,0 @@
----
-name: Crash report
-about: Report a crash of the editor while in-use
-labels: bug, crash
----
-
-<!--
-If you have a reproducer for the crash you've experienced, please make sure
-to include a demangled stacktrace (i.e. pass it to `c++filt`) produced
-by an instance of the editor built in debug mode (`make debug=yes`).
--->
-
-### Steps <!-- what steps allow reproducing the crash? -->
-
-### Outcome/Stacktrace <!-- what is the outcome of the above steps? is there any stacktrace? -->

.github/ISSUE_TEMPLATE/crash_report.yml

@@ -0,0 +1,62 @@
+name: Crash report
+description: Report a crash of the editor while in-use
+labels: bug, crash
+title: "[BUG][CRASH] "
+body:
+
+    - type: markdown
+      attributes:
+        value: |
+            Please make sure to [search issues](https://github.com/mawww/kakoune/issues?q=is%3Aissue) before creating a new one, to avoid duplicates and centralise conversations.
+
+            If you need to have a question about the editor itself (options, behaviour, code…) answered, make sure to check the [documentation](https://github.com/mawww/kakoune/tree/master/doc/pages) (also available via the `doc` command in the editor) or drop by [IRC](https://web.libera.chat/?channels=#kakoune) to get instant feedback.
+
+    - type: input
+      attributes:
+          label: "Version of Kakoune"
+          description: "If unsure, use the output of command: `kak -version`"
+          placeholder: "v2020.12.31"
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: "Reproducer"
+          description: "What are the steps to follow to reproduce the issue?"
+          placeholder: |
+              If any specific configuration or environment settings are required to reproduce the issue, also describe them here.
+      validations:
+        required: true
+
+    - type: textarea
+      attributes:
+          label: "Outcome"
+          description: "What is the outcome of the reproducing steps above?"
+          placeholder: |
+              If the editor printed any error messages, or if you managed to obtain a backtrace, also document them here. Make sure to demangle the stacktrace by passing it to the `c++filt` command.
+
+              Note that triggering the issue in the editor compiled in debug mode will produce more helpful messages, please consider re-building with `make debug=yes` to help us out.
+      validations:
+        required: true
+
+    - type: textarea
+      attributes:
+          label: "Expectations"
+          description: "What was the expected outcome of the reproducing steps above?"
+          placeholder: |
+              If the reproducing steps are self-evident, the expectations are simply “the editor should not crash”. In that case, you may ignore this field.
+      validations:
+        required: false
+
+    - type: textarea
+      attributes:
+          label: "Additional information"
+          description: "Any other information that may be relevant to diagnosing the issue should be documented here"
+          placeholder: |
+              Examples of relevant information:
+
+              * What OS and distribution are you using?
+              * Are you running an experimental branch (i.e. not `master`)?
+              * Is the issue reproducible in other terminals?
+      validations:
+        required: false