Add option to create a diff

[jmetertea]

Description

Add option to create a diff

Motivation and Context

Another valid option for contributing

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• [X ] My code follows the code style of this project.
• [ X] I have updated the documentation accordingly.

[FSchumacher]

Thanks for the patch.
I changed the formatting slightly. The char > should be encoded as   and I like a space before the beginning of a tag inside a sentence.