styles(index.js): relocate some code
chore(index.js): add comment
fix(utility functions): relocate the checkUserOnline() to API routes module
refactor(*): rename the passed object as kernel

Before:
- We have 2 different name used on the passed object of instance methods

After:
- The passed object as kernel, so that we are having a consistent things here. So, let's stick with kernel instead of kabam.