chore: bump workspace package versions for v2.1.0 release (#44)

- @showwhat/core, @showwhat/configurator, @showwhat/openfeature, showwhat: 2.0.0 → 2.1.0
- @repo/docs, @repo/webapp: bumped to 2.0.0

chore: bump all packages to v2.0.0

Breaking changes since v1.0.1 warrant a major version bump:
- showwhat() returns bulk Resolutions with success discriminant
- preset defaults replaced with overrides that lock fields
- listKeys() moved from DefinitionWriter to DefinitionReader

fix: reference version in CI

chore: move non-npm packages to @repo namespace