Updated contributing guidelines and added issue template

Author: squidfunk

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,26 @@
+## Description
+
+[Description of the bug]
+
+### Expected behavior
+
+[What you expected to happen]
+
+### Actual behavior
+
+[What is actually happening]
+
+### Steps to reproduce the bug
+
+1. [First step]
+2. [Second step]
+3. [and so on...]
+
+### Package versions
+
+* terraform-aws-github-ci: `...`
+* terraform: `...`
+
+### System information
+
+* OS: [The operating system you're running]

CONTRIBUTING.md

@@ -31,7 +31,7 @@ Please consider what kind of change it is:
 
 * For a **major feature**, first open an issue and outline your proposal so
   that it can be discussed. This will also allow us to better coordinate our
-  efforts, prevent duplication of work, and help you to craft the change so
+  efforts, prevent duplication of work and help you to craft the change so
   that it is successfully accepted into the project.
 
 * **Small features and bugs** can be crafted and directly submitted as a pull