Added additional clarification, fixed typos

[milesburton]

Before submitting a Pull Request, please test your code.

If you created a new feature, then create the unit test function, too.

# COMPILE
npm run build

# RE-WRITE TEST PROGRAMS IF REQUIRED
npm run test:template

# BUILD TEST PROGRAM
npm run build:test

# DO TEST
npm run test

Learn more about the CONTRIBUTING

[samchon]

Thanks for great emension.