Introduce issue templates (#21)

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,27 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+---
+
+**Describe the bug**
+Please provide a clear and concise description of what the bug is.
+ - optimalparallel version:
+ - Computing platform:
+ - Error message (if applicable):
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1.
+2.
+3.
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,15 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: enhancement
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is.
+
+**Describe the solution you would like to see**
+A clear and concise description of what you want to happen.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/ISSUE_TEMPLATE/general_issue.md

@@ -0,0 +1,6 @@
+---
+name: General issue
+about: Used for general issues, not covered by other templates.
+title: ''
+labels: ''
+---