Added issue templates

Author: samdark

.gitattributes

@@ -1,5 +1,6 @@
 # Ignore all test and documentation for archive
 /.editorconfig      export-ignore
+/.github            export-ignore
 /.gitattributes     export-ignore
 /.gitignore         export-ignore
 /.scrutinizer.yml   export-ignore

.github/CONTRIBUTING.md

@@ -0,0 +1,7 @@
+Contributing to Yii2
+====================
+
+- [Report an issue](https://github.com/yiisoft/yii2/blob/master/docs/internals/report-an-issue.md)
+- [Translate documentation or messages](https://github.com/yiisoft/yii2/blob/master/docs/internals/translation-workflow.md)
+- [Give us feedback or start a design discussion](http://www.yiiframework.com/forum/index.php/forum/42-general-discussions-for-yii-20/)
+- [Contribute to the core code or fix bugs](https://github.com/yiisoft/yii2/blob/master/docs/internals/git-workflow.md)

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,14 @@
+### What steps will reproduce the problem?
+
+### What's expected?
+
+### What do you get instead?
+
+
+### Additional info
+
+| Q                | A
+| ---------------- | ---
+| Yii vesion       |
+| PHP version      |
+| Operating system |

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,7 @@
+| Q             | A
+| ------------- | ---
+| Is bugfix?    | yes/no
+| New feature?  | yes/no
+| Breaks BC?    | yes/no
+| Tests pass?   | yes/no
+| Fixed issues  | comma-separated list of tickets # fixed by the PR, if any