refactor/perf: use nanocolors

[SukkaW]

What does it do?

Replace chalk with nanocolors. It is smaller and faster.

How to test

git clone -b use-nanocolors https://github.com/sukkaw/hexo.git
cd hexo
npm install
npm test

Screenshots

Pull request tasks

• Add test cases for the changes.
• Passed the CI test.

[coveralls]

Coverage remained the same at 98.162% when pulling 4a0e5f1 on SukkaW:use-nanocolors into b3bd7d4 on hexojs:master.

[SukkaW]

cc @tomap Here is the PR for nanocolors. I will update the other repos when I have time.