chore: remove assembly-sdk.md, simplify src/index to export *

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: priosshrsth

docs/assembly-sdk.md

@@ -1,14 +1 @@
-export {
-  AssemblyError,
-  AssemblyMissingApiKeyError,
-  AssemblyNoTokenError,
-  AssemblyInvalidTokenError,
-  AssemblyUnauthorizedError,
-  AssemblyForbiddenError,
-  AssemblyNotFoundError,
-  AssemblyValidationError,
-  AssemblyRateLimitError,
-  AssemblyServerError,
-  AssemblyConnectionError,
-  AssemblyResponseParseError,
-} from "src/errors/index";
+export * from "src/errors";