FEATURE: Introduce api.renderInOutlet (#23719)

Until now, plugins/themes had to follow very specific directory structures to set up plugin outlet connectors. This commit introduces a new `api.renderInOutlet` API which makes things much more flexible. Any Ember component definition can be passed to this API, and will then be rendered into the named outlet.

For example:

```javascript
import MyComponent from "discourse/plugins/my-plugin/components/my-component";
api.renderInOutlet('user-profile-primary', MyComponent);
```

When using this API alongside the gjs file format, components can be defined inline like

```javascript
api.renderInOutlet('user-profile-primary', <template>Hello world</template>);
```

docs/CHANGELOG-JAVASCRIPT-PLUGIN-API.md

@@ -7,6 +7,12 @@ in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.13.0] - 2023-10-05
+
+### Added
+
+- Introduces `renderInOutlet` API for rendering components into plugin outlets
+
 ## [1.12.0] - 2023-09-06
 
 ### Added