Add pseudolocalization tutorial (#5119)

Co-authored-by: Hugo Locurcio <hugo.locurcio@hugo.pro>

tutorials/i18n/index.rst

@@ -8,3 +8,4 @@ Internationalization
    internationalizing_games
    localization_using_gettext
    locales
+   pseudolocalization

tutorials/i18n/pseudolocalization.rst

@@ -0,0 +1,85 @@
+.. _doc_pseudolocalization:
+
+Pseudolocalization
+==================
+
+Introduction
+------------
+
+When creating a game, the process of localization usually starts when development
+has finished. This means that translations aren't available during development
+for testing whether the project is internationalized properly.
+
+Godot offers pseudolocalization as a way to test how robust the project is
+when it comes to locale changes. Pseudolocalization simulates changes that
+might take place during localization. This way, any issues regarding
+internationalization can be recognized early on during development.
+
+.. note:: The official demo for pseudolocalization can be used to play around with 
+          the various properties and observe their effects. You can
+          `download it from the godot-demo-projects GitHub repository <https://github.com/godotengine/godot-demo-projects/tree/4.0-dev/gui/pseudolocalization>`_.
+
+Enabling and configuring pseudolocalization
+-------------------------------------------
+
+Enabling pseudolocalization and the configurations related to it is as simple as
+toggling a checkbox in the project settings. These settings can be found in
+**Project → Project Settings → General → Internationalization → Pseudolocalization**
+after enabling the **Advanced** toggle in the project settings dialog:
+
+.. image:: img/pseudolocalization_settings.webp
+
+Pseudolocalization can also be :ref:`toggled at runtime from a script <doc_pseudolocalization_runtime>`.
+
+Pseudolocalization configurations
+---------------------------------
+
+Pseudolocalization in Godot can be set up according to the specific use case of the 
+project. Here are the pseudolocalization properties that can be configured through 
+project settings:
+
+- ``replace_with_accents``: Replaces all characters in the string with their accented
+  variants. *"The quick brown fox jumped over the lazy dog"* will be converted to
+  *"Ŧh̀é q́üíćḱ ḅŕôŵή f́ôx́ ǰüm̀ṕéd́ ôṽéŕ ŧh̀é łáźý d́ôǵ"* when this setting is enabled.
+  This can be used to spot untranslated strings that won't have accents,
+  but is also useful to check for missing glyphs in the font(s) used by the project.
+- ``double_vowels``: Doubles all the vowels in the string. It is a good approximation
+  to simulate expansion of text during localization.
+  This can be used to check for text that would overflow its container
+  (such as buttons).
+- ``fake_bidi``: Fake bidirectional text (simulates right-to-left text). This is useful to
+  simulate right-to-left writing systems to check for potential layout issues that would occur in languages using right-to-left scripts.
+- ``override``: Replaces all the characters in the string with an asterisk (``*``). This is useful for
+  quickly finding text that isn't being localized.
+- ``expansion_ratio``: Can be used in cases where doubling the vowels isn't a sufficient
+  approximation. This setting pads the string with underscores (``_``) and expands it by the given ratio.
+  An expansion ratio of ``0.3`` is sufficient for most practical cases; it will increase
+  the length of the string by 30%.
+- ``prefix`` and ``suffix``: These properties can be used to specify a prefix and suffix to wrap
+  the text in.
+- ``skip_placeholders``: Skips placeholders for string formatting like ``%s`` and ``%f``.
+  This is useful to identify places where more arguments are required for the formatted
+  string to display correctly.
+
+All of these properties can be toggled as needed according to the project's use case.
+
+.. _doc_pseudolocalization_runtime:
+
+Configuring pseudolocalization at runtime
+-----------------------------------------
+
+Pseudolocalization can be toggled at runtime using the
+:ref:`pseudolocalization_enabled<class_TranslationServer_property_pseudolocalization_enabled>` property
+in TranslationServer.
+However, if runtime configuration of pseudolocalization properties is required, 
+they can be directly configured using
+:ref:`ProjectSettings.set_setting(property, value) <class_ProjectSettings_method_set_setting>`
+and then calling
+:ref:`TranslationServer.reload_pseudolocalization() <class_TranslationServer_method_reload_pseudolocalization>`
+which reparses the pseudolocalization properties and reloads the pseudolocalization. 
+The following code snippet shall turn on ``replace_with_accents`` and ``double_vowels`` properties
+and then call ``reload_pseudolocalization()`` for the changes to get reflected::
+
+    ProjectSettings.set_setting("internationalization/pseudolocalization/replace_with_accents", true)
+    ProjectSettings.set_setting("internationalization/pseudolocalization/double_vowels", true)
+    TranslationServer.reload_pseudolocalization()