Update 06-Data-Container-Arrays.md

Feld sql hinzugefügt
Update 06-Data-Container-Arrays.md

Feld relation hinzugefügt
Update 06-Data-Container-Arrays.md

Feld sql zur Konfiguration hinzugefügt.
Moved "relation" description to separate table and fixed minor mistakes
Update 06-Data-Container-Arrays.md

Added sql in the config section
Added sql/relations in field section
Added new relations section
Update 06-Data-Container-Arrays.md

fixed wording
Fixed some english issues
Merge branch '3.0' into 3.1