[Development] Nominating Mitch Curtis for approver

[Jedrzej Nowacki]

I would like to propose Mitch Curtis for approver status.

https://codereview.qt-project.org/#q,owner:+mitch,n,z
https://codereview.qt-project.org/#dashboard,1001967

Mitch is working in the Digia Oslo office. In last few months he contributed 
more then 100 patches in different areas; mainly in documentation and date and 
time. He also put a lot of effort to triage and reproduce JIRA bugs. Lately he 
decided to explore Windows lands, and search for a dragon there. I'm sure that 
he will keep showing commitment to the Qt and interest in a clean, robust 
code.