Comments, pictures and more text fields for the reviews

Now you can add a comment for each individual review!
If you have further questions or criticism, just make a comment!

And for each product you can upload a picture, showing more details or colors of that product.

In addition we added a few more text fields for the reviews:
- Strengths (what is outstanding of the product?)
- Weaknesses (what is not so good?)
- Additional comments (anything else worth to mention?)
- Similar gear used (what gear did you ride in comparison to it?)