lint: Add Export documentation rules

With the `revive` linter replacing `golint` within `golangci-lint`, the check for exports having documentation has been disabled by default.

This should be re-enabled as all exports should have documentation and reviews are having to check for this unnecessarily.

```yml
linters:
enable:
- revive

linters-settings:
revive:
rules:
- name: exported
arguments:
- disableStutteringCheck

issues:
include:
- EXC0012 # EXC0012 revive: Annoying issue about not having a comment. The rare codebase has such comments
- EXC0014 # EXC0014 revive: Annoying issue about not having a comment. The rare codebase has such comments
```

See https://www.pixelstech.net/article/1650069870-golangci-lint-to-enable-comment-check-for-exported-functions