README: add to limitions notice about incremental chains and timelines

gsmolk · gsmolk · commit c3c05e83b680 · 2019-05-23T11:58:01.000+03:00
diff --git a/README.md b/README.md
@@ -43,6 +43,7 @@ Regardless of the chosen backup type, all backups taken with `pg_probackup` supp
 `pg_probackup` currently has the following limitations:
 * The server from which the backup was taken and the restored server must be compatible by the [block_size](https://postgrespro.com/docs/postgresql/current/runtime-config-preset#GUC-BLOCK-SIZE) and [wal_block_size](https://postgrespro.com/docs/postgresql/current/runtime-config-preset#GUC-WAL-BLOCK-SIZE) parameters and have the same major release number.
 * Remote mode is in beta stage.
+* Incremental chain can span only within one timeline. So if you have backup incremental chain taken from replica and it gets promoted, you would be forced to take another FULL backup.
 
 ## Installation and Setup
 ### Windows Installation
