Refactor documentation configuration for ReadTheDocs

- Moved the list of supported languages directly into the `html_context` dictionary in `conf.py`.
- Increased the maximum depth of the table of contents in `index.rst` from 2 to 3 for better navigation.

Author: adamzhang1987

docs/source/conf.py

@@ -70,17 +70,14 @@
 # for a list of supported languages.
 language = 'en'
 
-# List of supported languages
-languages = {
-    'en': 'English',
-    'zh_CN': '中文',
-}
-
 # -- Options for ReadTheDocs ------------------------------------------------
 
 # ReadTheDocs specific settings
 html_context = {
     'display_language_tabs': True,
     'current_language': language,
-    'languages': languages,
+    'languages': {
+        'en': 'English',
+        'zh_CN': '中文',
+    },
 }

docs/source/index.rst

@@ -7,7 +7,7 @@ Welcome to bt-python-sdk's documentation!
 =========================================
 
 .. toctree::
-   :maxdepth: 2
+   :maxdepth: 3
    :caption: Contents:
 
    README