Created readme file

Closes #3322080

README.md

+# File upload directory change
+
+This module allow the website administrator to change
+the location (public/private) of a file/image put in a field.
+
+For a full description of the module, visit the
+[project page](https://www.drupal.org/project/file_upload_directory_change).
+
+Submit bug reports and feature suggestions, or track changes in the
+[issue queue](https://www.drupal.org/project/issues/file_upload_directory_change).
+
+
+## Table of contents
+
+- Requirements
+- Installation
+- Configuration
+- Maintainers
+- Supporting organizations
+
+
+## Requirements
+
+This module requires no modules outside of Drupal core.
+
+
+## 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
+
+1. Define the private folder in settings.php of your drupal instance.
+   (if not already done)
+1. Be sure the private folder is created.
+1. Go to the file/image field configuration, in the form display of the content
+   type you want.
+1. Edit the field configuration and check "enable" for the configuration
+   "File upload directory change enabled"
+1. save the form diplay settings.
+
+
+**Using the directory change functionnality**
+
+1. Go in a content you just changed the content type configuration
+1. Edit the content
+1. check the checkbox "Change file location" near the image field.
+1. Save the content
+1. if your file directory was public before saving, now it's defined as private
+1. if your file directory was private before saving, now it's defined as public
+
+
+## Maintainers
+
+- Olivier - [olivierg](https://www.drupal.org/u/olivierg)
+
+## Supporting organizations
+- [ISSA](https://www.drupal.org/issa)
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