Rename beta SDKs to public preview SDKs in readme (#1998)

* Rename beta SDKs to public preview SDKs in readme

* More details in installation steps

* Update README.md

Author: ramya-stripe

README.md

@@ -255,18 +255,17 @@ You can disable this behavior if you prefer:
 Stripe.enableTelemetry = false;
 ```
 
-### Beta SDKs
+### Public Preview SDKs
 
-Stripe has features in the beta phase that can be accessed via the beta version of this package.
-We would love for you to try these and share feedback with us before these features reach the stable phase.
-To install a beta version of stripe-java follow steps [installation steps above](#installation) using the beta library version.
+Stripe has features in the [public preview phase](https://docs.stripe.com/release-phases) that can be accessed via the beta version of this package.
+We would love for you to try these as we incrementally release new features and improve them based on your feedback.
 
-> **Note**
-> There can be breaking changes between beta versions. Therefore we recommend pinning the package version to a specific version. This way you can install the same version each time without breaking changes unless you are intentionally looking for the latest beta version.
+The public preview SDKs are different versions of the same package as the stable SDKs. These versions are appended with `-beta.X` such as `25.1.0-beta.1`. To install, choose the version that includes support for the preview feature you are interested in by reviewing the [releases page](https://github.com/stripe/stripe-java/releases/) and then use it [installation steps above](#installation).
 
-We highly recommend keeping an eye on when the beta feature you are interested in goes from beta to stable so that you can move from using a beta version of the SDK to the stable version.
+> **Note**
+> There can be breaking changes between two versions of the public preview SDKs without a bump in the major version. Therefore we recommend pinning the package version to a specific version. This way you can install the same version each time without breaking changes unless you are intentionally looking for the latest public preview SDK.
 
-If your beta feature requires a `Stripe-Version` header to be sent, set the `Stripe.stripeVersion` field by calling `Stripe.addBetaVersion`:
+If your beta feature requires a `Stripe-Version` header to be sent, set the `Stripe.stripeVersion` field by calling `Stripe.addBetaVersion` (available only in the public preview SDKs):
 
 > **Note**
 > Beta version headers can only be set in beta versions of the library.