JSDoc: fix spacing for details table

Before:
![before](https://f.cloud.github.com/assets/55838/1392084/4d18e48e-3c06-11e3-94f7-86c32a3bac5d.png)

After:
![after](https://f.cloud.github.com/assets/55838/1392083/454ad046-3c06-11e3-86e2-c86d2f941f42.png)