Fixed broken link in faq.md

[Widdin]

The speed scheduler was linked to "http://rocketmap.readthedocs.io/en/develop/scanning-method/Speed-Scheduler.html" which isn't a valid site. The correct is with non-capital letters "/speed-scheduler.html"

Description

Motivation and Context

To lead people to the correct site instead of having to ask.

How Has This Been Tested?

Clicked it => Didn't work
Searched for the correct website.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.