docs: update config example in LDClient constructor docs (#224)

**Requirements**

- [ ] I have added test coverage for new or changed functionality
- [x] I have followed the repository's [pull request submission
guidelines](../blob/main/CONTRIBUTING.md#submitting-pull-requests)
- [ ] I have validated my changes against all supported platform
versions

**Related issues**

Followup to [this
discussion](https://github.com/launchdarkly/ld-docs-private/pull/4382/files#r1619543723)
in launchdarkly/ld-docs-private#4382, which
clarified that this example is out of date.

**Describe the solution you've provided**

Update the code sample in the LDClient constructor API docs to use
`.Events` correctly.

**Describe alternatives you've considered**

If this seems confusing or too much, we could also just remove lines
124-128, and build the `Configuration` without setting any options:

```
var config = Configuration.Builder("my-sdk-key").Build();
var client = new LDClient(config);
```

**Additional context**

previously opened as
launchdarkly/dotnet-server-sdk-private#340

pkgs/sdk/server/src/LdClient.cs

@@ -120,10 +120,7 @@ public sealed class LdClient : IDisposable, ILdClient
         /// <param name="config">a client configuration object (which includes an SDK key)</param>
         /// <example>
         /// <code>
-        ///     var config = Configuration.Builder("my-sdk-key")
-        ///         .AllAttributesPrivate(true)
-        ///         .EventCapacity(1000)
-        ///         .Build();
+        ///     var config = Configuration.Builder("my-sdk-key").Build();
         ///     var client = new LDClient(config);
         /// </code>
         /// </example>