Add more GitHub topics

[ehmicky]

This is related to #27.

GitHub topics are important to make repositories easy to search/find and increase GitHub traffic.

I think adding as many topics as possible (20) is good too as it helps users finding the repository with alternative keywords.

[sindresorhus]

@ehmicky Can you suggest some topics that you'd like to see added?

[ehmicky]

awesome
awesome-list
node
cross-platform
portable
portability
compatibility
windows
macos
macosx
linux
unix
bsd
os
operating-system
os-identification
shell
cmd
environment-variables
signal

[bcoe]

👋 topics are new to me, have never configured them on my repos.

I'm happy to add some, is it something you have permission to do? or do you need me to do so.

[ehmicky]

I don't have the permission to set topics.

[ehmicky]

@bcoe What do you think?