[docs] add --only option

resources/docs/run-single-rule.md

@@ -0,0 +1,17 @@
+Sometimes, we want to apply just one rule at a time. But modifying `rector.php` config over and over again is tedious and can lead to mistakes.
+
+To run single rule, we can use `--only` CLI option. Just add quoted class name:
+
+```bash
+vendor/bin/rector --only="Rector\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodRector"
+```
+
+Mind the quotes, as both Win and *nix system require them to pick up the full class name string (both single and double are supported).
+
+## Rule must be registered in `rector.php`
+
+We can run only the rules explicitly registered in `rector.php` or loaded sets. This way configured rules load explicit configuration the same way we would run the rule by calling `vendor/bin/rector`.
+
+<br>
+
+In case Rector is not able to pick up your class name, see [feature pull-request](https://github.com/rectorphp/rector-src/pull/6441#issuecomment-2497474323) that describes all supported formats.

src/Documentation/DocumentationMenuFactory.php

@@ -23,13 +23,14 @@ public function create(): array
     {
         return [
             'First Steps' => [
-                $this->documentationMenuItemFactory->createSection('integration-to-new-project', 'New Project', true),
+                $this->documentationMenuItemFactory->createSection('integration-to-new-project', 'New Project'),
                 $this->documentationMenuItemFactory->createSection('define-paths', 'Define Paths'),
                 $this->documentationMenuItemFactory->createSection('set-lists', 'Set Lists'),
-                $this->documentationMenuItemFactory->createSection('levels', 'Levels', true),
+                $this->documentationMenuItemFactory->createSection('levels', 'Levels'),
                 $this->documentationMenuItemFactory->createSection('attributes', 'PHP 8.0 Attributes', true),
                 $this->documentationMenuItemFactory->createSection('composer-based-sets', 'Composer-Based Sets', true),
                 $this->documentationMenuItemFactory->createInternalLink(FindRuleController::class, 'Find Rules'),
+                $this->documentationMenuItemFactory->createSection('run-single-rule', 'Run single rule', true),
                 $this->documentationMenuItemFactory->createSection(
                     'ignoring-rules-or-paths',
                     'Ignoring Rules or Paths'
@@ -69,7 +70,7 @@ public function create(): array
                 ),
                 $this->documentationMenuItemFactory->createSection('rules-overview', 'Rules Overview'),
                 $this->documentationMenuItemFactory->createSection('creating-a-node-visitor', 'Creating Node Visitor'),
-                $this->documentationMenuItemFactory->createSection('how-to-run-on-php-53', 'Run on PHP 5.3', true),
+                $this->documentationMenuItemFactory->createSection('how-to-run-on-php-53', 'Run on PHP 5.3'),
             ],
         ];
     }