docs: fix final section on best practices (ngworker#180)

## PR Checklist

Please check if your PR fulfills the following requirements:

- [x] The commit message follows our guidelines: CONTRIBUTING.md#commit
- [ ] Tests for the changes have been added (for bug fixes / features)
- [x] Docs have been added / updated (for bug fixes / features)

## PR Type

What kind of change does this PR introduce?

<!-- Please check the one that applies to this PR using "x". -->

```
[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[x] Documentation content changes
[ ] Other... Please describe:
```

## What is the current behavior?

The final code example in the best practices section was cut out and
incomplete.

## What is the new behavior?

The final code example in the best practices section
(LumberjackLogFactory) is restored and complete.

## Does this PR introduce a breaking change?

```
[ ] Yes
[x] No
```

packages/docs/lumberjack-docs-app/docs/best-practices.md

@@ -250,5 +250,13 @@ export class AppComponent implements OnInit {
   readonly #scope = 'Forest App';
 
   ngOnInit(): void {
-    const helloFore
+    const helloForest = this.#logFactory
+      .createInfoLog('Hello, Forest!')
+      .withScope(this.scope)
+      .withPayload(this.payload)
+      .build();
+
+    this.#lumberjack.log(helloForest);
+  }
+}
 ```