Add Option to Process only Multi Line Comments

For some projects, inline comments are more clear when adjacent to the code linearly. This pull request adds an optional flag to process only multi line comments and leave inline comments in the code.

The default is _false_, to be consistent with current usage.

**Example**:

```js
/**
 * This comment will get processed and documented.
 */

// This comment will remain in the code and NOT documented.
```