rel: Prepare v1.13.0 release (#89)

## Which problem is this PR solving?
Prepares the next release of otel-config-go package.

## Short description of the changes
- Updates version to 1.13.0 in version.go
- Adds changelog entry including breaking changes section
- Update Readme with OTel project version, includes adding a specific
entry for otel contrib package versions, and the minimum Go version

## How to verify that this has the expected result
The v1.13.0 release can be published.

CHANGELOG.md

@@ -1,5 +1,20 @@
 # otel-config-go changelog
 
+## v1.13.0 (2023-11-22)
+
+### 💥 Breaking Changes 💥
+
+The OpenTelemetry SDK moved the metrics packages into the main SDK packages with the latest release as it's now GA.
+If you used the metrics packages, you may need to update your import paths to reflect the new package.
+
+Additionally, the OpenTelenetry SDK's minimum Go version is now 1.20.
+
+### Maintenance
+
+- Bump OTel dependencies (#84) | @MikeGoldsmith
+- Add dependency groups for otel and otel contrib packages (#79) | @MikeGoldsmith
+- Bump OTel core and contrib packages to latest (#90) | @MikeGoldsmith
+
 ## v1.12.1 (2023-09-21)
 
 ### Maintenance

README.md

@@ -4,11 +4,16 @@ This project is a configuration layer that chooses default values for configurat
 
 Latest release built with:
 
-- OpenTelemetry Go [v1.18.0/v0.41.0](https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.18.0)
+- OpenTelemetry Go [v1.21.0/v0.44.0](https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.21.0)
+- OpenTelemetry Go Contrib [v1.21.1/v0.46.1](https://github.com/open-telemetry/opentelemetry-go-contrib/releases/tag/v1.21.1)
 - OpenTelemetry Semantic Conventions [v1.21.0](https://github.com/open-telemetry/opentelemetry-go/tree/main/semconv/v1.21.0)
 
 (Note: semantic conventions to be updated to match upstream in next release)
 
+Minimum Go Version: `1.20`
+
+See the OpenTelemetry SDK's [compatability matrix](https://github.com/open-telemetry/opentelemetry-go#compatibility) for more information.
+
 ## Getting started
 
 ```bash

otelconfig/version.go

@@ -1,3 +1,3 @@
 package otelconfig
 
-const version = "1.12.1"
+const version = "1.13.0"