Add example dir placeholder for paged-attention

example/ck_tile/18_paged_attention/CMakeLists.txt

+# set example name according to its directory name (without the leading digits followed by an underscore)
+get_filename_component(DIR_NAME "${CMAKE_CURRENT_SOURCE_DIR}" NAME)
+string(REGEX REPLACE "^[0-9]+_" "" TRIMMED_DIR_NAME "${DIR_NAME}")
+
+# add prefix "tile_example_" to the processed directory name
+set(EXAMPLE_NAME "tile_example_${TRIMMED_DIR_NAME}")
+
+message("[POYENC] example name: ${EXAMPLE_NAME}")
+add_executable(${EXAMPLE_NAME} EXCLUDE_FROM_ALL paged_attention.cpp)
\ No newline at end of file

example/ck_tile/18_paged_attention/paged_attention.cpp

+#include <iostream>
+
+int main() { std::cout << "hello ck-tile example" << std::endl; }