Add Arabic language files

Here are all the language files for Arabic!
Thanks to Montassar and Seif for their hard work to localize the
entire game in such a short timespan.

desktop_version/lang/ar/meta.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<langmeta>
+    <active>1</active>
+
+    <!-- should be lowercase because menu style, and should be in the language itself -->
+    <nativename>العربية</nativename>
+
+    <!-- English translation by X -->
+    <credit>Eternal Dream Arabization</credit>
+
+    <!-- On the language screen, hard limit 40 8x8 characters. Space/Z/V sets this as the language -->
+    <action_hint>اضغط مسافة، زر Z، أو زر V للاختيار</action_hint>
+
+    <!-- Same as above, but for a gamepad button (hard limit 40 8x8 characters) -->
+    <gamepad_hint>اضغط {button} للاختيار</gamepad_hint>
+
+    <!-- Enable automatic word wrapping instead of having to manually insert newlines -->
+    <autowordwrap>1</autowordwrap>
+
+    <!-- Enable automatic full-caps display of selected menu options ([SELECTED] not selected) -->
+    <toupper>1</toupper>
+
+    <!-- When automatically uppercasing, map i to İ (for Turkish) -->
+    <toupper_i_dot>0</toupper_i_dot>
+
+    <!-- When automatically uppercasing, allow ~ to be used to stop the next letter from being uppercased (for Irish) -->
+    <toupper_lower_escape_char>0</toupper_lower_escape_char>
+
+    <!-- Enable for RTL languages like Arabic or Hebrew -->
+    <rtl>1</rtl>
+
+    <!-- The indication that a certain menu option or button is selected -->
+    <menu_select>[ {label} ]</menu_select>
+    <menu_select_tight>[{label}]</menu_select_tight>
+
+    <!-- The filename of the font to use. For example, "font_cn" means font_cn.png and font_cn.fontmeta. -->
+    <font>font_ar</font>
+</langmeta>