Update 12-ParallelExecution.md
Update 12-ParallelExecution.md

Fix some small issues with in code examples
tiger-seo/Codeception,SunDrop/Codeception,TehJoE/Codeception,may-den/Codeception,nett55/Codeception,mkudenko/Codeception,vml-rmott/Codeception,janthurau/Codeception,orhan-swe/Codeception,Naktibalda/Codeception,JakobReiter/Codeception,janhenkgerritsen/Codeception,janhenkgerritsen/Codeception,Vitafy/Codeception,Naktibalda/Codeception,EspadaV8/Codeception,pecinaon/Codeception,JarJak/Codeception,tasselchof/Codeception,namnv609/Codeception,arduanov/Codeception,bizmate/Codeception,vml-rmott/Codeception,yhbyun/Codeception,JarJak/Codeception,Pyrotoxin/Codeception,kt81/Codeception,Vreasy/Codeception,SunDrop/Codeception,Vitafy/Codeception,namnv609/Codeception,JakobReiter/Codeception,cjaoude/Codeception,yhbyun/Codeception,cjaoude/Codeception,hubbyist/Codeception,hubbyist/Codeception,tasselchof/Codeception,EspadaV8/Codeception,orhan-swe/Codeception,fbidu/Codeception,Naktibalda/Codeception,kt81/Codeception,justintilson/Codeception,Codeception/Codeception,arduanov/Codeception,may-den/Codeception,TehJoE/Codeception,nett55/Codeception,sergeyklay/Codeception,tasselchof/Codeception,justintilson/Codeception,pecinaon/Codeception,bizmate/Codeception,sergeyklay/Codeception,Codeception/base,Vreasy/Codeception,Codeception/Codeception,mkudenko/Codeception,fbidu/Codeception,Codeception/base,Codeception/base,pitpit/Codeception,Pyrotoxin/Codeception,janthurau/Codeception,tiger-seo/Codeception,pitpit/Codeception