Adds `.editorconfig`, copied byte-for-byte from `sneak/dnswatcher` (blob `2fe0ce0`). This is the small, safe half of #59; the `.golangci.yml` half is deferred — adopting the org-standard config surfaces ~2,990 lint findings on vaultik and needs a separate lint-cleanup decision (see #59). Hence `refs #59`, not `closes`.
`make check` and `docker build .` are green (a static config file does not affect them). Left open for review (not merged).
Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #60
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
