Update sbt_plugin.rst
Update sbt_plugin.rst

fix grammar
pwielgolaski/gatling,gatling/gatling,MykolaB/gatling,MykolaB/gatling,wiacekm/gatling,timve/gatling,timve/gatling,MykolaB/gatling,timve/gatling,gatling/gatling,wiacekm/gatling,gatling/gatling,gatling/gatling,pwielgolaski/gatling,wiacekm/gatling,wiacekm/gatling,gatling/gatling,wiacekm/gatling,pwielgolaski/gatling,timve/gatling,pwielgolaski/gatling,MykolaB/gatling