Update dashboard.md (#391)
Update dashboard.md (#391)

Renamed incorrect link
from:
https://github.com/stryker-mutator/stryker-net/blob/master/docs/Reporters.md 
to: 
https://github.com/stryker-mutator/stryker-net/blob/master/docs/reporters.md
stryker-mutator/stryker-mutator.github.io,stryker-mutator/stryker-mutator.github.io,stryker-mutator/stryker-mutator.github.io,stryker-mutator/stryker-mutator.github.io