This PR adds `golangci-lint` based on the configuration from
`coder/coder`
([here](https://github.com/coder/coder/blob/main/.golangci.yaml)) then
migrated to v2 using `golangci-lint migrate` plus the addition of few
more linters.
---------
Signed-off-by: Callum Styan <callumstyan@gmail.com>
## Changes made
- Added avatars for each contributor
- Updated validation steps to account for avatars, if the avatar field
exists
- Went ahead and made some slog changes, ahead of @cstyan's refactor PR
