Add issue templates

This should make the issue reporting flow a bit smoother.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,13 @@
+---
+name: Bug report
+about: Report incorrect or outdated documentation
+title: ''
+labels: bug
+assignees: ''
+---
+
+**Your Godot version:**
+
+**Issue description:**
+
+**URL to the documentation page:**

.github/ISSUE_TEMPLATE/enhancement_request.md

@@ -0,0 +1,13 @@
+---
+name: Enhancement request
+about: Suggest new documentation or improving existing documentation
+title: ''
+labels: enhancement
+assignees: ''
+---
+
+**Your Godot version:**
+
+**Issue description:**
+
+**URL to the documentation page (if already existing):**

.github/ISSUE_TEMPLATE/support_question.md

@@ -0,0 +1,18 @@
+---
+name: Support question
+about: Asking a question about the engine or something not working
+title: 'IMPORTANT: This repository does not accept support questions.'
+labels: archived
+assignees: ''
+---
+
+**IMPORTANT, PLEASE READ**
+
+Support questions are not accepted on this repository.
+Please use one of the other community channels instead, such as Discord:
+
+https://godotengine.org/community
+
+Do not submit to this repository or your issue will be closed.
+
+**IMPORTANT, PLEASE READ**