readme: fix link, release doc: add postgres information

README.md

@@ -15,7 +15,7 @@ _a simple image hosting service_
     2. [Api](#api)
 3. [Administration](#administration)
     1. [Backups](#backups)
-    2. [0.4 to 0.5 Migration Guide](#0-4-to-0-5-migration-guide)
+    2. [0.4 to 0.5 Migration Guide](#04-to-05-migration-guide)
         1. [Overview](#overview)
         2. [Upgrade Configuration](#upgrade-configuration)
         3. [Configuration Updates](#configuration-updates)

releases/0.5.0.md

@@ -44,7 +44,7 @@
 
 - [ini and json5](#ini-and-json5)
 - [Client Pool Size](#client-pool-size)
-- [0.3 Migration Path](#0-3-migration-path)
+- [0.3 Migration Path](#03-migration-path)
 - [Prepare Upgrade Endpoint](#prepare-upgrade-endpoint)
 
 
@@ -66,14 +66,51 @@ will extract metadata for any uploads that have not had their metadata extracted
 If you have any custom configuration, note that some media-related configuration values have been
 moved. See [Media Configuration](#media-configuration) below.
 
+pict-rs 0.5 now supports postgres for metadata storage. It is possible to upgrade directly from 0.4
+to 0.5 with postgres, rather than upgrading to 0.5 with sled and then making the migration later.
+This process is documented in the
+[pict-rs readme](https://git.asonix.dog/asonix/pict-rs#upgrading-directly-to-postgres).
+
 More information can be found in the
-[pict-rs readme](https://git.asonix.dog/asonix/pict-rs#04-to-05-migration-guide).
+[pict-rs 0.4 to 0.5 migration guide](https://git.asonix.dog/asonix/pict-rs#04-to-05-migration-guide).
 
 
 ## Descriptions
 
 ### Postgres Repo
 
+One of the most anticipated features of pict-rs 0.5 is the support for postgres for metadata
+storage. This makes pict-rs (mostly) stateless, enabling it to be scaled horizontally across
+multiple physical or virtual hosts. It also simplifies administration and backup processes for folks
+who are already running a postgres server for other reasons.
+
+Configuring postgres is simple. The `repo` section of the pict-rs configuration now supports more
+than just `sled`.
+
+In the configuration file
+```toml
+[repo]
+type = 'postgres'
+url = 'postgres://user:password@host:5432/db'
+```
+
+With environment variables
+```bash
+PICTRS__REPO__TYPE=postgres
+PICTRS__REPO__URL=postgres://user:password@host:5432/db
+```
+
+On the commandline
+```bash
+pict-rs run filesystem -p ./data postgres -u 'postgres://user:password@host:5432/db'
+```
+
+It is possible to update from 0.4 directly to 0.5 with postgres, this process is documented in the
+[pict-rs readme](https://git.asonix.dog/asonix/pict-rs#upgrading-directly-to-postgres).
+
+It is possible to migrate to postgres after first upgrading to 0.5. This is also ducmented in the
+[pict-rs readme](https://git.asonix.dog/asonix/pict-rs#sled-to-postgres-migration).
+
 
 ### Media Proxy