Fix gocritic & golint(revive) issues in the codebase

[vharsh]

This issue is strictly for someone who has recently up Golang & would like to fix some code formatting issues.

I've recently fixed a small issue with GolangCI-lint(#105) in #145 & now the project has many warnings/suggestions & now they need fixing, currently those linters are disabled but do enable them after fixing all the issues.

Steps

1. Learn a bit about GolangCI-Lint from it's official docs & a few blogs
2. Uncomment the enabled linters in GolangCI-Lint
3. Fix the code comment errors manually or figure out if the revive tool can autofix things for you(recommended).
4. Raise a PR & make sure to sign all your commits