chore: update README (#95)

Author: stainless-bot

README.md

@@ -8,8 +8,6 @@
 
 The Lithic Java SDK provides convenient access to the Lithic REST API from applications written in Java. It includes helper classes with helpful types and documentation for every request and response property.
 
-This package is currently in beta (pre-v1.0.0). We expect some breaking changes to rarely-used areas of the SDK, and appreciate your [feedback](https://www.github.com/lithic-com/lithic-java/issues).
-
 The Lithic Java SDK is similar to the Lithic Kotlin SDK but with minor differences that make it more ergonomic for use in Java, such as `Optional` instead of nullable values, `Stream` instead of `Sequence`, and `CompletableFuture` instead of suspend functions.
 
 ## Documentation
@@ -356,3 +354,14 @@ LithicClient client = LithicOkHttpClient.builder()
     .sandbox()
     .build();
 ```
+
+## Semantic Versioning
+
+This package generally follows [SemVer](https://semver.org/spec/v2.0.0.html) conventions, though certain backwards-incompatible changes may be released as minor versions:
+
+1. Changes to library internals which are technically public but not intended or documented for external use. _(Please open a GitHub issue to let us know if you are relying on such internals)_.
+2. Changes that we do not expect to impact the vast majority of users in practice.
+
+We take backwards-compatibility seriously and work hard to ensure you can rely on a smooth upgrade experience.
+
+We are keen for your feedback; please open an [issue](https://www.github.com/lithic-com/lithic-java/issues) with questions, bugs, or suggestions.