Update issue templates

Author: naki40

.github/ISSUE_TEMPLATE/bug.md

@@ -0,0 +1,16 @@
+---
+name: Bug
+about: Issue for bugs
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+#### Problem description
+
+#### Steps to reproduce
+
+#### Expected behaviour
+
+#### Screenshots if applicable

.github/ISSUE_TEMPLATE/epic.md

@@ -0,0 +1,17 @@
+---
+name: Epic
+about: Issue for epics
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+#### Description
+
+#### Epic specification link
+
+#### Issues in this epic:
+
+- [ ] Issue 1
+- [ ] Issue 2

.github/ISSUE_TEMPLATE/story.md

@@ -0,0 +1,19 @@
+---
+name: Story
+about: Issue for stories
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+#### Description
+
+#### Epic specification link
+
+#### Story specification link
+
+#### Issues in this story:
+
+- [ ] Issue 1
+- [ ] Issue 2