docs: add GitSpo mentions badge

Author: gajus

README.md

@@ -1,5 +1,6 @@
 # babel-plugin-react-css-modules
 
+![[GitSpo Mentions](https://gitspo.com/mentions/gajus/babel-plugin-react-css-modules)](https://gitspo.com/badges/gajus/babel-plugin-react-css-modules?style=flat-square)
 [![Travis build status](http://img.shields.io/travis/gajus/babel-plugin-react-css-modules/master.svg?style=flat-square)](https://travis-ci.org/gajus/babel-plugin-react-css-modules)
 [![NPM version](http://img.shields.io/npm/v/babel-plugin-react-css-modules.svg?style=flat-square)](https://www.npmjs.org/package/babel-plugin-react-css-modules)
 [![Canonical Code Style](https://img.shields.io/badge/code%20style-canonical-blue.svg?style=flat-square)](https://github.com/gajus/canonical)
@@ -260,19 +261,19 @@ To add support for different CSS syntaxes (e.g. SCSS), perform the following two
     }
   }
   ```
-  
+
   Postcss plugins can have options specified by wrapping the name and an options object in an array inside your config
-  
+
   ```json
     "plugins": [
       ["postcss-import-sync2", {
         "path": ["src/styles", "shared/styles"]
       }],
       "postcss-nested"
     ]
-  ```  
-   
-  
+  ```
+
+
 ### Custom Attribute Mapping
 
 You can set your own attribute mapping rules using the `attributeNames` option.