Update README to reflect current feature set

The README listed several implemented features as unsupported
(prepared statements, query cancellation, SSL/TLS) and referenced
the wrong SSL dependency (net_ssl instead of ssl). Also missing
any mention of SCRAM-SHA-256 auth and the examples directory.

Author: SeanTAllen

README.md

@@ -18,31 +18,41 @@ Please note that if this library encounters a state that the programmers thought
 * `use "postgres"` to include this package
 * `corral run -- ponyc` to compile your application
 
-This library has a transitive dependency on [ponylang/net_ssl](https://github.com/ponylang/net_ssl). It requires a C SSL library to be installed. Please see the [net_ssl installation instructions](https://github.com/ponylang/net_ssl?tab=readme-ov-file#installation) for more information.
+This library has a transitive dependency on [ponylang/ssl](https://github.com/ponylang/ssl). It requires a C SSL library to be installed. Please see the [ssl installation instructions](https://github.com/ponylang/ssl?tab=readme-ov-file#installation) for more information.
 
 ## API Documentation
 
 [https://ponylang.github.io/postgres](https://ponylang.github.io/postgres)
 
+## Examples
+
+The [examples](examples/) directory contains self-contained programs demonstrating different parts of the library. See [examples/README.md](examples/README.md) for descriptions.
+
 ## Postgres API Support
 
 This library aims to support the Postgres API to the level required to use Postgres from Pony in ways that the Pony community needs. We do not aim to support the entire API surface. If there is functionality missing, we will happily accept high-quality pull requests to add additional support so long as  they don't come with additional external dependencies or overly burdensome maintenance.
 
 ### Authentication
 
-Only MD5 password authentication is supported. KerberosV5, cleartext, SCM, GSS, SSPI, and SASL authentication methods are not supported.
+MD5 password and SCRAM-SHA-256 authentication are supported. SCRAM-SHA-256 is the default authentication method in PostgreSQL 10 and later.
+
+KerberosV5, cleartext, SCM, GSS, SSPI, SCRAM-SHA-256-PLUS (channel binding), and certificate authentication methods are not supported.
+
+### SSL/TLS
+
+Optional SSL/TLS encryption is supported. Pass `SSLRequired` with an `SSLContext` to `ServerConnectInfo` to enable encrypted connections. If the server refuses SSL negotiation, the connection fails. Plaintext connections are the default.
 
 ### Commands
 
-Basic API commands related to querying are supported at this time. Some functionality that isn't yet supported is:
+Simple queries, parameterized queries (extended query protocol), named prepared statements, and query cancellation are supported.
+
+Some functionality that isn't yet supported is:
 
 * Supplying connection configuration to the server
-* Prepared statements (aka Extended Queries)
 * Pipelining queries
 * Function calls
 * COPY operations
-* Cancelling in progress requests
-* Session encryption
+* LISTEN/NOTIFY
 
 Note the appearance of an item on the above list isn't a guarantee that it will be supported in the future.