Add StyleCI configuration.

Author: bobthecow

.styleci.yml

@@ -0,0 +1,21 @@
+risky: true
+
+preset: symfony
+
+enabled:
+  - align_double_arrow
+  - native_function_invocation
+  - ordered_use
+  - strict
+
+disabled:
+  - native_function_invocation_symfony
+  - no_superfluous_phpdoc_tags_symfony
+  - pow_to_exponentiation
+  - pre_increment
+  - unalign_double_arrow
+  - yoda_style
+
+finder:
+  name:
+    - "*.php"

README.md

@@ -5,6 +5,7 @@ Ruler is a simple stateless production rules engine for PHP 5.3+.
 
 [![Package version](http://img.shields.io/packagist/v/ruler/ruler.svg?style=flat-square)](https://packagist.org/packages/ruler/ruler)
 [![Build status](https://img.shields.io/github/workflow/status/bobthecow/Ruler/Unit%20Tests/main.svg?style=flat-square)](https://github.com/bobthecow/Ruler/actions?query=branch:main)
+[![StyleCI](https://styleci.io/repos/1906921/shield)](https://styleci.io/repos/1906921)
 
 Ruler has an easy, straightforward DSL
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