Release Version 0.3.0

[beeme1mr]

Release checklist:

• [x] Release spec v0.3.0
• [x] Update spec badge on the org readme
• [x] Create issues in the SDK repos containing the new requirements
  • https://github.com/open-feature/java-sdk/issues/45
  • https://github.com/open-feature/node-sdk/issues/159
  • https://github.com/open-feature/golang-sdk/issues/44
  • https://github.com/open-feature/python-sdk/issues/8
  • https://github.com/open-feature/dotnet-sdk/issues/48
• [x] Update the documentation git submodule

Spec v0.3.0 badge