Add Section 18.11 - Add spaces inside curly braces

Fixes #593

README.md

@@ -1587,6 +1587,16 @@ Other Style Guides
     console.log(foo[0]);
     ```
 
+  - [18.11](#18.11) <a name='18.11'></a> Add spaces inside curly braces.
+
+    ```javascript
+    // bad
+    const foo = {clark: 'kent'};
+
+    // good
+    const foo = { clark: 'kent' };
+    ```
+
 **[⬆ back to top](#table-of-contents)**
 
 ## Commas

packages/eslint-config-airbnb/rules/style.js

@@ -66,8 +66,8 @@ module.exports = {
     'no-underscore-dangle': 0,
     // disallow the use of Boolean literals in conditional expressions
     'no-unneeded-ternary': 0,
-    // require or disallow padding inside curly braces
-    'object-curly-spacing': 0,
+    // require padding inside curly braces
+    'object-curly-spacing': [2, 'always'],
     // allow just one var statement per function
     'one-var': [2, 'never'],
     // require assignment operator shorthand where possible or prohibit it entirely