Removing 2.x versions post 3.0.0-preview1 (#2967)

* Update changelog.md

* Removing 2.x changes after the split to relv2

* Update 3.0.0-preview2 bug fixes changelog.md

Author: JoshLozensky

changelog.md

@@ -1,3 +1,11 @@
+========
+
+**See [rel/v2 branch changelog](https://github.com/AzureAD/microsoft-identity-web/blob/rel/v2/changelog.md#2200) for changes to all 2.x.x versions after 2.18.1.**
+
+**The changes listed in the rel/v2 changelog are also in the 3.x.x versions of Id Web but are not listed here.**
+
+========
+
 3.0.1
 =========
 - Updated to Microsoft.IdentityModel.* 8.0.1
@@ -27,36 +35,9 @@
 - Change GetSignedAssertion public API. See issue [#2853](https://github.com/AzureAD/microsoft-identity-web/issues/2853) for details.
 - Update to latest .NET 9 preview 4. See issue [#2877](https://github.com/AzureAD/microsoft-identity-web/pull/2877) for details.
 
-3.0.0-preview1
-=========
-### Breaking changes
-- Remove netcoreapp3.1 support, see issue [#2262](https://github.com/AzureAD/microsoft-identity-web/issues/2262) for details.
-- Remove net5.0 support from Microsoft.Identity.Web.UI, see issue [#2711](https://github.com/AzureAD/microsoft-identity-web/issues/2711) for details.
-
-### New features
-- Microsoft.Identity.Web can be conditionally built on `.net9.0-preview`, see issue [#2702](https://github.com/AzureAD/microsoft-identity-web/issues/2702) for details.
-- Microsoft.Identity.Web nows processes the `AcceptHeader` and `ContentType` if provided, see issue [#2806](https://github.com/AzureAD/microsoft-identity-web/issues/2806) for details.
-- Target Microsoft.IdentityModel 7x in OWIN targets, see issue [#2785](https://github.com/AzureAD/microsoft-identity-web/issues/2785) for details. 
-
-========
-
-**See [rel/v2 changelog](https://github.com/AzureAD/microsoft-identity-web/blob/rel/v2/changelog.md#2200) for full list of added features to 3.0.0**.
-  
-========
-
-2.19.0
-=========
-- Updated to Microsoft.IdentityModel.* 7.6.0
-
-### New features
-- Id Web now provides a `.WithUser()` modifier to the Microsoft Graph queries (like `WithAppOnly()`). See issue [#2855](https://github.com/AzureAD/microsoft-identity-web/issues/2855) for details.
-- Id Web now provides a base class for implementing a custom `IAuthorizationHeaderProvider`. See issue [#2856](https://github.com/AzureAD/microsoft-identity-web/issues/2856) for details.
-
 ### Bug Fixes
-- Id Web now processes the extra query parameters when included as part of the authority. See issue [#2697](https://github.com/AzureAD/microsoft-identity-web/issues/2697) for details.
 - If `Logging:LogLevel:Microsoft.Identity.Web` is assigned to `None`, no default logger is initialized and Microsoft.Identity.Web does not record any logs. See [#2816](https://github.com/AzureAD/microsoft-identity-web/pull/2816) for details. 
 - `GraphAuthenticationProvider` checks that the `RequestInformation.URI` is a Graph URI before appending the authorization header, resolving [#2710](https://github.com/AzureAD/microsoft-identity-web/issues/2710). See PR [#2818](https://github.com/AzureAD/microsoft-identity-web/pull/2818) for details.
-- `TokenAcquisition` processes the error code `AADSTS1000502 (The provided certificate is not within its specified validity window)`. See PR [#2840](https://github.com/AzureAD/microsoft-identity-web/pull/2840) for details.
 
 3.0.0-preview1
 =========