Fix function comments based on best practices from Effective Go

[Daanikus]

Every exported function in a program should have a doc comment. The first sentence should be a summary that starts with the name being declared. From effective go.

I generated this with CodeLingo and I'm keen to get some feedback, but this is automated so feel free to close it and just say "opt out" to opt out of future CodeLingo outreach PRs.

[Daanikus]

Looks like these changes, few as they are, are pretty solid. Let me know if you find this useful :smile: If not, are there any fixes I can do to make it useful?

Note: I've only updated functions that CodeLingo can rewrite nicely, but you can install it on GitHub to review your PRs automatically and find all issues.