Update README.md

Closes #3339143

README.md

-### Introduction
+# Group clone
 
-This module allows cloning groups and their content along with any referenced
+The Group clone module allows cloning groups and their content along with any referenced
 entities.
 
+For a full description of the module, visit the
+[project page](https://www.drupal.org/project/group_clone).
 
-### Configuration
+Submit bug reports and feature suggestions, or track changes in the
+[issue queue](https://www.drupal.org/project/issues/search/group_clone).
 
-Configuration can be found in Groups -> Settings -> Cloning settings.
+
+## Table of contents
+
+- Requirements
+- Installation
+- Configuration
+- Reverting
+- Extending
+- Maintainers
+
+
+## Requirements
+
+This module requires the following modules:
+
+- [Group](https://www.drupal.org/project/group)
+
+
+## Installation
+
+- Install as you would normally install a contributed Drupal module. For further
+information, see
+[Installing Drupal Modules](https://www.drupal.org/docs/extending-drupal/installing-drupal-modules).
+
+
+## Configuration
+
+- Configuration can be found in Groups -> Settings -> Cloning settings.
 An administrator (administer group permission) can define which group types
 can be cloned and what should the default cloning behavior for different
 group content types be. After group cloning is enabled for a group type,
 all groups of that type will have a "Clone" tab.
 
 
-### Reverting
+## Reverting
 
 After a group is cloned, the cloning can be reverted from the "Clone" tab.
 This deletes all the entities that have been cloned and doesn't affect the
 source group in any way.
 
 
-### Extending
+## Extending
 
 To implement a specific cloning method for any group content type plugin,
 create a new GroupContentCloner plugin in any module. See
 `Drupal\group_clone\Annotation\GroupContentCloner` and
 `Drupal\group_clone\Plugin\GroupContentCloner\GroupContentClonerInterface`.
+
+
+## Maintainers
+
+Current maintainers:
+- Marcin Grabias - [Graber](https://www.drupal.org/u/graber)