Add changelog entries

Author: geo2a

ouroboros-consensus-cardano/changelog.d/20241127_163624_georgy.lukyanov_892_checksum_snaphot_file.md

@@ -0,0 +1,5 @@
+### Breaking
+
+- The changes in `ouroboros-consensus-cardano` renamed `DiskSnapshot` to `DiskSnapshotName` and introduced a new type `DiskSnapshot` that carries a checksum. This change is propagated here as well.
+
+

ouroboros-consensus/changelog.d/20241128_084625_georgy.lukyanov_892_checksum_snaphot_file.md

@@ -0,0 +1,13 @@
+### Breaking
+
+- Rename `DiskSnapshot` to `DiskSnapshotName`; `DiskSnapshot` is now a record of a `DiskSnapshotName` and a CRC checksum of the data.
+- When writing a ledger state snapshot to disk, calculate the state's CRC checksum and write it to a separate file, which is named the same as the snapshot file, plus the `.crc` extension.
+- When reading a snapshot file, calculate its checksum and compare it to the value in the corresponding `.crc` file. Return an error if either the checksum file does not exist or the checksum is wrong.
+- To support the previous item, change the error type of the `readSnapshot` from `ReadIncrementalErr` to the extended `ReadSnaphotErr`.
+
+- Make `Ouroboros.Consensus.Util.CBOR.readIncremental` compute the checksum of the data as it is read.
+
+### Non-breaking
+
+- Introduce an explicit `Ord` instance for `DiskSnapshotName` that compares the values on `dsnNumber`.
+