Added templates for github (fixes #117)

.gitattributes

@@ -2,4 +2,4 @@
 /docs export-ignore
 /.gitignore export-ignore
 /.travis.yml export-ignore
-/phpunit.xml.dist export-ignore
+/.github export-ignore

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,14 @@
+## Affected Version
+
+Show version numbers by pasting the output of `composer info --direct`.
+Alternatively, hover over the SilverStripe logo in the CMS to basic version information.
+
+## Description
+
+Describe expected and observed behaviour.
+For visual issues, please include browser version and screenshots.
+Please read https://docs.silverstripe.org/en/contributing/issues_and_bugs/
+
+## Steps to Reproduce
+
+Help us with step-by-step instructions.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,5 @@
+Thanks for contributing, you're awesome! :star:
+Please describe expected and observed behaviour, and what you're fixing.
+For visual fixes, please include tested browsers and screenshots.
+Search for related existing issues and link to them if possible.
+Please read https://github.com/UndefinedOffset/SortableGridField/blob/master/CONTRIBUTING.md