chore: update for available versions (#4638)

* chore: update for available versioins.

* Update _migrate_self_postgres_plan_migration_path.md

Signed-off-by: Iain Cox <[email protected]>

* Update _migrate_self_postgres_plan_migration_path.md

Signed-off-by: Iain Cox <[email protected]>

* chore: update on review.

---------

Signed-off-by: Iain Cox <[email protected]>

Author: billy-the-fish

_partials/_migrate_self_postgres_plan_migration_path.md

@@ -1,22 +1,27 @@
 
 import SupportMatrix from "versionContent/_partials/_migrate_self_postgres_timescaledb_compatibility.mdx";
 
-Best practice is to always use the latest version of TimescaleDB. Subscribe to our releases on GitHub or use $CLOUD_LONG 
+Best practice is to always use the latest version of $TIMESCALE_DB. Subscribe to our releases on GitHub or use $CLOUD_LONG 
 and always run the latest update without any hassle. 
 
-Check the following support matrix against the versions of $TIMESCALE_DB and $PG that you are running currently 
+Check the following support matrix against the versions of $TIMESCALE_DB and $PG that you are running currently
 and the versions you want to update to, then choose your upgrade path.
 
-For example, to upgrade from $TIMESCALE_DB 2.13 on $PG 13 to $TIMESCALE_DB 2.18.2 you need to:
-1. Upgrade $TIMESCALE_DB to 2.15
-1. Upgrade $PG to 14, 15 or 16.
-1. Upgrade $TIMESCALE_DB to 2.18.2.
+For example, to upgrade from $TIMESCALE_DB 2.13 on $PG 13 to the latest $TIMESCALE_DB version you need to:
+1. Upgrade $TIMESCALE_DB to 2.15.0 (last version fully supporting $PG 13)
+1. Upgrade $PG to 15, 16, 17, or 18
+1. Upgrade $TIMESCALE_DB to the latest available version (2.24.x or higher)
 
-You may need to [upgrade to the latest $PG version][upgrade-pg] before you upgrade TimescaleDB. Also,
+Older $TIMESCALE_DB versions may not be available in package repositories. If you need a specific intermediate
+version that is no longer packaged, you can [build from source][build-from-source] or upgrade directly
+to the latest version that supports your current $PG version before upgrading $PG.
+
+You may need to upgrade to the latest $PG version before you upgrade $TIMESCALE_DB. Also,
 if you use [$TOOLKIT_LONG][install-toolkit], ensure the `timescaledb_toolkit` extension is >=  
 v1.6.0 before you upgrade $TIMESCALE_DB extension.
 
 <SupportMatrix />
 
 [install-toolkit]: /self-hosted/:currentVersion:/tooling/install-toolkit/
 [upgrade-pg]: /self-hosted/:currentVersion:/upgrades/upgrade-pg/#plan-your-upgrade-path
+[build-from-source]: /self-hosted/:currentVersion:/install/installation-source/