[issue #2221] [issue #788] Lombok now adds nullity annotations.

Which 'flavour' is defined in lombok.config; applied to toString, equals, canEqual, and plural-form of `@Singular`.

website/templates/features/EqualsAndHashCode.html

@@ -54,7 +54,7 @@
 			If a getter exists for a field to be included, it is called instead of using a direct field reference. This behaviour can be suppressed:<br />
 			<code>@EqualsAndHashCode(doNotUseGetters = true)</code>
 		</p><p>
-			If the class (or an enclosing class) has either the <code>@org.eclipse.jdt.annotation.NonNullByDefault</code> or the <code>@javax.annotation.ParametersAreNonnullByDefault</code> annotation, the parameter of the generated <code>equals</code> method will have the appropriate <code>@Nullable</code> annotation; JDK8+ is required when you do this. <span class="since">(since 1.18.12)</span>.
+			If you have configured a nullity annotation flavour via <a href="configuration"><code>lombok.config</code></a> key <code>lombok.addNullAnnotations</code>, the parameter of both the generated <code>equals</code> method as well as any <code>canEqual</code> method is annotated with a nullable annotation. This is required if you use a <code>@NonNullByDefault</code> style annotation in combination with strict nullity checking.
 		</p>
 	</@f.smallPrint>
 </@f.scaffold>