Add Contribution guide and Issue/PR templates (#3)

Author: paulbalaji

.github/CONTRIBUTING.md

@@ -0,0 +1,10 @@
+# Repository contributions
+
+## Contributions policy
+We are currently not accepting public contributions (but we do plan to in later releases and we’ll keep you osted on this). However, we are taking issues and we do want your [feedback](../README.md#give-us-feedback).
+
+## Coding standards
+See the [GDK for Unity C# coding standards guide](../coding-standards.md).
+
+## Getting started
+See [About the SpatialOS Unity GDK](https://docs.improbable.io/unity/alpha/get-started) for details on how to get started using the Unity GDK.

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,29 @@
+We are accepting issues and we want your [feedback](../README.md#give-us-feedback).
+
+-------
+
+#### Description
+Describe your issue.
+
+## Expected behaviour
+<!--- Tell us what should happen. -->
+
+## Current behaviour
+<!--- Tell us what happens instead of the expected behaviour. -->
+
+## Possible solution
+<!--- This is not obligatory but if you have a preference, please suggest a fix for the bug. -->
+
+## Steps to reproduce
+<!--- Provide an unambiguous set of steps to reproduce this bug. Include code snippets if relevant. -->
+1.
+2.
+3.
+4.
+
+## Environment
+<!--- What were you trying to accomplish? -->
+<!--- Please include your spatial diagnose output in full. -->
+<!--- Please detail your OS & Unity versions. -->
+
+<!--- Provide a general summary of the issue in the title field above. -->

.github/pull_request_template.md

@@ -0,0 +1,16 @@
+**Contributions**: We are not currently taking public contributions - see our [contributions](CONTRIBUTING.md) policy. However, we are accepting issues and we do want your [feedback](https://github.com/spatialos/gdk-for-unity#give-us-feedback).
+
+-------
+
+#### Description
+Describe your changes here.
+
+#### Tests
+How did you test these changes prior to submitting this pull request?
+What automated tests are included in this PR?
+
+#### Documentation
+How is this documented (for example: release note, upgrade guide, feature page, in-code documentation)?
+
+#### Primary reviewers
+If your change will take a long time to review, you can name at most two primary reviewers who are ultimately responsible for reviewing this request. @ mention them.