Update issue templates (#2452)

Author: gpetiot

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: OCaml Community Forum
+    url: https://discuss.ocaml.org/
+    about: Please ask and answer questions here.
+  - name: OCaml Community Discord
+    url: https://discord.gg/cCYQbqN
+    about: Please ask and answer questions here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -2,7 +2,7 @@
 name: Feature request
 about: Suggest an idea for this project
 title: 'Feature request: ...'
-labels: Kind/Feature-request
+labels: 'Kind/feature-request'
 assignees: ''
 
 ---

.github/ISSUE_TEMPLATE/question.md

@@ -0,0 +1,14 @@
+---
+name: Question
+about: Do you have a question about ocamlformat?
+title: 'Question: ...'
+labels: 'Kind/question'
+assignees: ''
+
+---
+
+Please give as much context as possible.
+
+Is your question related to a specific OCaml version?
+Is your question related to a specific OCamlFormat version?
+Is your question related to a specific formatting profile or option?

.github/ISSUE_TEMPLATE/style_suggestion.md

@@ -0,0 +1,18 @@
+---
+name: Style suggestion
+about: Suggest a different formatting style for this project
+title: 'Style suggestion: ...'
+labels: 'Kind/style-suggestion'
+assignees: ''
+
+---
+
+**Current formatting**
+Please copy-paste your code and the formatting that is currently applied to it.
+
+**Describe the formatting you'd like**
+A clear and concise description of what you want to happen.
+
+**Additional context**
+Add any other context about the style request here.
+What justifies ocamlformat adding this new style?