add release notes

Author: ssg

src/SimpleBase.csproj

@@ -24,6 +24,23 @@
         <PackageReadmeFile>README.md</PackageReadmeFile>
 		<PackageReleaseNotes>
 			<![CDATA[
+# 5.0.0
+
+## Breaking changes
+- TryDecode/TryEncode methods no longer throw
+- Base85 methods with `Ipv6` in them renamed to `IPv6` to match with .NET
+- `numBytesWritten` parameters have all been renamed to `bytesWritten` to match with .NET
+- The target framework was changed to .NET 8.0 around 4.2.0, but the version change did not
+  reflect that breaking change, although in practice it shouldn't cause many issues.
+
+## New features
+- Base62
+- Base45
+- Multibase now supports Base45
+- Base32 now has a non-throwing `TryDecodeUInt64()` method
+
+## Improvements
+- `Multibase.Encode()` now allocates less memory
             
 ]]>
 		</PackageReleaseNotes>