raposza/tools: platform/raposza-target-2x/README.md

<!-- Copyright (c) 2026 bentzn --> <!-- SPDX-License-Identifier: Apache-2.0 --> # raposza-target-2x Translation implementation for Canton 2.9 and 2.10, over Ledger API v1. This is the complete client implementation: participant identity, parties, users, the active contract set, single contracts, tra