v5.4.0

Added

• BASE_CONTEXT is now exported from the package index.
• New additive additionalContext option on createDID/updateDID: an array
  of context entries appended after BASE_CONTEXT on create (or after the
  supplied didDocument's own @context), and after the carried-forward
  @context on update, deduplicated (strings by value, objects by JSON
  serialization). It is mutually exclusive with context, which remains the
  full-override escape hatch; passing both throws. No document bytes change:
  the result matches what context: [...BASE_CONTEXT, extra] already produced.

Changed

• Documented the context option's semantics on both interfaces: it replaces
  the document's @context wholesale, and updateDID without it preserves the
  prior entry's context, falling back to BASE_CONTEXT only when the document
  never had one.