[*]: add github config files

.gitattributes

@@ -5,6 +5,7 @@
 /.scrutinizer.yml export-ignore
 /.styleci.yml export-ignore
 /.gitattributes export-ignore
+/.github export-ignore
 /.gitignore export-ignore
 /.travis.yml export-ignore
 /phpcs.php_cs export-ignore

.github/CONTRIBUTING.md

@@ -0,0 +1,22 @@
+# How to Contribute
+
+## Pull Requests
+
+1. Create your own [fork](https://help.github.com/articles/fork-a-repo) of this repo
+2. Create a new branch for each feature or improvement
+3. Send a pull request from each feature branch to the **master** branch
+
+It is very important to separate new features or improvements into separate
+feature branches, and to send a pull request for each branch. This allows me to
+review and pull in new features or improvements individually.
+
+## Style Guide
+
+All pull requests must adhere to the [PSR-2 standard](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md).
+
+## Unit Testing
+
+All pull requests must be accompanied by passing PHPUnit unit tests and
+complete code coverage.
+
+[Learn about PHPUnit](https://github.com/sebastianbergmann/phpunit/)

.github/FUNDING.yml

@@ -0,0 +1,4 @@
+github: [voku]
+patreon: voku
+tidelift: packagist/voku%2Fsimple-cache
+custom: https://www.paypal.me/moelleken

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,7 @@
+#### What is this feature about (expected vs actual behaviour)?
+
+#### How can I reproduce it?
+
+#### Does it take minutes, hours or days to fix?
+
+#### Any additional information?