v4.0.0-beta.20

What's Changed

• Preview template assets in a modal from the editor by @takkyun in #136
• Cut image-upload gocyclo complexity and ban //nolint:gocyclo in CI by @takkyun in #138
• issue #137: clarify template import location in admin nav and docs by @takkyun in #139

Full Changelog: v4.0.0-beta.19...v4.0.0-beta.20