docs: warn about .dockerignore when embedding (#609)

* Add notice for .dockerignore issues in embed.md

* Add french notice for .dockerignore issues in embed.md

* Add chinese notice for .dockerignore issues in embed.md

* Fix whitespaces in documentation

* Apply suggestions for translations

Co-authored-by: Jerry Ma <jesse2061@outlook.com>
Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>

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Co-authored-by: Jerry Ma <jesse2061@outlook.com>
Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>