Chore: update README.md with karma js config example for grep
Chore: update README.md with karma js config example for grep

maksimr/karma-mocha,danthareja/karma-mocha-extended,webdev1001/karma-mocha,cbankester/karma-mocha,karma-runner/karma-mocha,dej611/karma-mocha,mochajs/karma-mocha,Dignifiedquire/karma-mocha