Docs update

Author: fsbraun

README.rst

@@ -156,7 +156,35 @@ Example::
 
     TEXT_EDITOR = "djangocms_text.contrib.text_ckeditor4.ckeditor4"
 
+Rich text editor configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``TEXT_EDITOR`` setting points to a ``RTEConfig`` object. You can create your custom
+``RTEConfig`` instance.  The following attributes are available:
+
+- name (str): The name of the RTE configuration.
+- config (str): The configuration string.
+- js (Iterable[str]): An iterable of JavaScript files to include.
+- css (dict): A dictionary of CSS files to include.
+- admin_css (Iterable[str]): An iterable of CSS files for the admin interface only.
+- inline_editing (bool): Whether to enable inline editing.
+- child_plugin_support (bool): Whether to support child plugins.
 
+The default configuration is:
+
+.. code-block:: python
+    RTEConfig(
+        name="tiptap",
+        config="TIPTAP",
+        js=("djangocms_text/bundles/bundle.tiptap.min.js",),
+        css={"all": ("djangocms_text/css/bundle.tiptap.min.css",)},
+        admin_css=("djangocms_text/css/tiptap.admin.css",),
+        inline_editing=True,
+        child_plugin_support=True,
+    )
+
+You can use the ``admin_css`` attribute to include CSS files that you need to be loaded into the
+dialog window, e.g., to declare custom colors or other styles.
 
 Inline editing feature
 ~~~~~~~~~~~~~~~~~~~~~~

djangocms_text/editors.py

@@ -433,12 +433,18 @@ class RTEConfig:
         config (str): The configuration string.
         js (Iterable[str]): An iterable of JavaScript files to include.
         css (dict): A dictionary of CSS files to include.
+        admin_css (Iterable[str]): An iterable of CSS files for the admin interface only.
+        inline_editing (bool): Whether to enable inline editing.
+        child_plugin_support (bool): Whether to support child plugins.
 
     Attributes:
         name (str): The name of the RTE configuration.
         config (str): The configuration string.
         js (Iterable[str]): An iterable of JavaScript files to include.
         css (dict): A dictionary of CSS files to include.
+        admin_css (Iterable[str]): An iterable of CSS files for the admin interface only.
+        inline_editing (bool): Whether to enable inline editing.
+        child_plugin_support (bool): Whether to support child plugins.
     """
 
     def __init__(