Snapshot of JC3636W518EN kit before demo folder cleanup

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2-Program Example/Demo_Arduino/library/lvgl/examples/widgets/btnmatrix/index.rst

@@ -0,0 +1,22 @@
+
+Simple Button matrix
+""""""""""""""""""""""
+
+.. lv_example:: widgets/btnmatrix/lv_example_btnmatrix_1
+  :language: c
+
+
+Custom buttons
+""""""""""""""""""""""
+
+.. lv_example:: widgets/btnmatrix/lv_example_btnmatrix_2
+  :language: c
+
+
+Pagination
+""""""""""""""""""""""
+
+.. lv_example:: widgets/btnmatrix/lv_example_btnmatrix_3
+  :language: c
+
+