Docs: improve a bit the docs for "requireObjectKeysOnNewLine" rule

Closes gh-1976

Author: ficristo

lib/rules/require-object-keys-on-new-line.js

@@ -3,7 +3,11 @@
  *
  * Types: `Boolean` or `Object`
  *
- * Values: `true` or Object with `allExcept` Array of quoted identifiers which are exempted
+ * Values:
+ *  - `true`
+ *  - `Object`:
+ *     - `'allExcept'` array of exceptions:
+ *       - `'sameLine'` ignores the rule if all the keys and values are on the same line
  *
  * #### Example
  *
@@ -31,15 +35,15 @@
  * };
  * ```
  *
- * ##### Valid
+ * ##### Valid for `{ "allExcept": ["sameLine"] }`
  *
  * ```js
  * var a = {
  *     b: 'b', c: 'c'
  * };
  * ```
  *
- * ##### Invalid
+ * ##### Invalid for `{ "allExcept": ["sameLine"] }`
  *
  * ```js
  * var a = {