docs: remove deprecated API references and simplify navigation in documentation

Author: ya7010

docs/docs/api/tppt_exception.md

@@ -1,6 +1,6 @@
 # Examples
 
-Here are some examples of how to use TPPT in various scenarios. For detailed API reference, see [Core API Reference](api/tppt.md), [PPTX API Reference](api/tppt_pptx.md), [DML API Reference](api/tppt_pptx_dml.md), [Shape API Reference](api/tppt_pptx_shape.md), [Text API Reference](api/tppt_pptx_text.md), [Template API Reference](api/tppt_template.md), [Types API Reference](api/tppt_types.md), and [Exception API Reference](api/tppt_exception.md).
+Here are some examples of how to use TPPT in various scenarios. For detailed API reference, see [API Reference](api/tppt.md).
 
 ## Basic Presentation
 

docs/docs/api/tppt_pptx.md

@@ -1,6 +1,6 @@
 # Usage Guide
 
-This guide will walk you through the basic usage of TPPT. For detailed API reference, see [Core API Reference](api/tppt.md), [PPTX API Reference](api/tppt_pptx.md), [DML API Reference](api/tppt_pptx_dml.md), [Shape API Reference](api/tppt_pptx_shape.md), [Text API Reference](api/tppt_pptx_text.md), [Template API Reference](api/tppt_template.md), [Types API Reference](api/tppt_types.md), and [Exception API Reference](api/tppt_exception.md).
+This guide will walk you through the basic usage of TPPT. For detailed API reference, see [API Reference](api/tppt.md).
 
 ## Creating a Presentation
 

docs/docs/api/tppt_pptx_dml.md

@@ -73,14 +73,6 @@ nav:
   - Home: index.md
   - Installation: installation.md
   - Usage: usage.md
-  - API Reference:
-      - tppt: api/tppt.md
-      - tppt.pptx: api/tppt_pptx.md
-      - tppt.pptx.dml: api/tppt_pptx_dml.md
-      - tppt.pptx.shape: api/tppt_pptx_shape.md
-      - tppt.pptx.text: api/tppt_pptx_text.md
-      - tppt.template: api/tppt_template.md
-      - tppt.types: api/tppt_types.md
-      - tppt.exception: api/tppt_exception.md
+  - API Reference: api/tppt.md
   - Examples: examples.md
   - Contributing: contributing.md