Added issue templates

Author: Przemog1

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,23 @@
+---
+name: Bug report
+about: Report a bug or problem encountered while using Nabla
+---
+
+## Describe the bug
+<!-- A clear and concise description of what the bug is. -->
+
+## Steps to Reproduce
+
+<!-- Please describe how the bug you've encountered can be reproduced -->
+
+## Environment
+
+<!-- Please provide the following information -->
+
+* **OS:**
+* **CPU:**
+* **GPU:**
+* **GPU driver version:**
+* **Compiler:**
+* **branch:**
+* **commit hash:**

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,21 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+---
+
+## Description
+
+<!-- Please describe your suggestion -->
+
+## Environment
+
+<!-- Please provide the following information -->
+
+* **OS:**
+* **CPU:**
+* **GPU:**
+* **GPU driver version:**
+* **Compiler:**
+* **branch:**
+* **commit hash:**
+