3.0.0

This release bumps the major version as there are multiple backwards incompatible changes with the 2.x series:

• Unstructured translations are not supported anymore
• Support fallback chains when resolving translations
• Require a default locale when using Trans
• Return nil for unitialised embed in struct

Additionally:

• The minimum Elixir version to use Trans is 1.11
• There are multiple fixes, doc improvements and test refactors