Change build setup to build one language at a time

_config.yml

@@ -6,6 +6,7 @@ author: the TCLab Team
 copyright: "2025"
 logo: tclab.png
 exclude_patterns: ["_build", ".venv", "*.ipynb_checkpoints", ".pipenv"]
+only_build_toc_files: true
 
 # Force re-execution of notebooks on each build.
 # See https://jupyterbook.org/content/execute.html

_toc.de.yml

@@ -0,0 +1,15 @@
+# Table of contents
+# Learn more at https://jupyterbook.org/customize/toc.html
+
+format: jb-book
+root: U00_Intro
+chapters:
+- file: U01_DSP_Basics
+- file: U02_Project
+  sections:
+    - file: U02_1_Input
+    - file: U02_2_Freq_Shift
+    - file: U02_3_Low_Pass
+    - file: U02_4_Sync
+    - file: U02_5_Output
+

_toc.en.yml

@@ -2,22 +2,13 @@
 # Learn more at https://jupyterbook.org/customize/toc.html
 
 format: jb-book
-root: U00_Intro
+root: U00_Intro.en
 chapters:
-- file: U00_Intro.en
-- file: U01_DSP_Basics
 - file: U01_DSP_Basics.en
-- file: U02_Project
 - file: U02_Project.en
   sections:
-    - file: U02_1_Input
     - file: U02_1_Input.en
-    - file: U02_2_Freq_Shift
     - file: U02_2_Freq_Shift.en
-    - file: U02_3_Low_Pass
     - file: U02_3_Low_Pass.en
-    - file: U02_4_Sync
     - file: U02_4_Sync.en
-    - file: U02_5_Output
     - file: U02_5_Output.en
-