Feat/mixed changes (#502)

* remove trailing whitespace

Signed-off-by: ccdd13 <78702084+ccdd13@users.noreply.github.com>

* safe include config.php with __DIR__

* replace doc url for $datetime_format from function.date.php to datetime.format.php

Signed-off-by: ccdd13 <ccdd13@users.noreply.github.com>

* put $auth_users & $readonly_users together

Signed-off-by: ccdd13 <ccdd13@users.noreply.github.com>

* update $datetime_format

Signed-off-by: ccdd13 <ccdd13@users.noreply.github.com>

Co-authored-by: ammm ccdd12 <mamok43076@dashseat.com>
Co-authored-by: ccdd13 <ccdd13@users.noreply.github.com>

README.md

@@ -4,7 +4,7 @@
 [![Live demo](https://img.shields.io/badge/Live-Demo-brightgreen.svg?style=flat-square)](https://tinyfilemanager.github.io/demo/)
 [![Live demo](https://img.shields.io/badge/Help-Docs-lightgrey.svg?style=flat-square)](https://github.com/prasathmani/tinyfilemanager/wiki)
 [![GitHub Release](https://img.shields.io/github/release/qubyte/rubidium.svg?style=flat-square)](https://github.com/prasathmani/tinyfilemanager/releases)
- [![GitHub License](https://img.shields.io/github/license/prasathmani/tinyfilemanager.svg?style=flat-square)](https://github.com/prasathmani/tinyfilemanager/blob/master/LICENSE) 
+ [![GitHub License](https://img.shields.io/github/license/prasathmani/tinyfilemanager.svg?style=flat-square)](https://github.com/prasathmani/tinyfilemanager/blob/master/LICENSE)
 [![Paypal](https://img.shields.io/badge/Donate-Paypal-lightgrey.svg?style=flat-square)](https://www.paypal.me/prasathmani)
 > TinyFileManager is web based file manager and it is a simple, fast and small file manager with a single file, multi-language ready web application for storing, uploading, editing and managing files and folders online via web browser. The Application runs on PHP 5.5+, It allows the creation of multiple users and each user can have its own directory and a build-in support for managing text files with cloud9 IDE and it supports syntax highlighting for over 150+ languages and over 35+ themes.
 
@@ -39,12 +39,12 @@ Default username/password: **admin/admin@123** and **user/12345**.
 To enable/disable authentication set `$use_auth` to true or false.
 
 
-### :loudspeaker: Features 
+### :loudspeaker: Features
 
 - :cd: Open Source, light and extremely simple
 - :iphone: Mobile friendly view for touch devices
-- :information_source: Basic features likes Create, Delete, Modify, View, Quick Preview, Download, Copy and Move files 
-- :arrow_double_up: Ajax Upload, Ability to drag & drop, upload from URL, multiple files upload with file extensions filter 
+- :information_source: Basic features likes Create, Delete, Modify, View, Quick Preview, Download, Copy and Move files
+- :arrow_double_up: Ajax Upload, Ability to drag & drop, upload from URL, multiple files upload with file extensions filter
 - :file_folder: Ability to create folders and files
 - :gift: Ability to compress, extract files (`zip`, `tar`)
 - :sunglasses: Support user permissions - based on session and each user root folder mapping
@@ -58,7 +58,7 @@ To enable/disable authentication set `$use_auth` to true or false.
 - :bangbang: lots more...
 
 
-### <a name=license></a>License, Credit  
+### <a name=license></a>License, Credit
 
 - Available under the [GNU license](https://github.com/prasathmani/tinyfilemanager/blob/master/LICENSE)
 - Original concept and development by github.com/alexantr/filemanager