Go's semantic import versioning requires v2+ modules to include the
major version in the module path. This enables using proper version
tags (v3.x.x) instead of pseudo-versions.
Updated module path: code.gitcaddy.com/server/v3
Followup to https://github.com/go-gitea/gitea/pull/35734.
- Move `codeformat` folder to `tools`
- Add `tools` to `GO_DIRS`
- Move `misspellings.csv` to `assets` so we can lint the whole `tools`
directory without filter shenanigans.
---------
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>