Add heirarchical build to mimic pico-examples

.gitignore

@@ -32,3 +32,4 @@
 *.app
 
 **/build
+.vscode

CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.12)
+
+# Pull in PICO SDK (must be before project)
+include(pico_sdk_import.cmake)
+
+project(pico_examples C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+
+# Initialize the SDK
+pico_sdk_init()
+
+# Example projects
+add_subdirectory(pack)

pack/CMakeLists.txt

@@ -0,0 +1,4 @@
+if (NOT PICO_NO_HARDWARE)
+    add_subdirectory(display)
+    add_subdirectory(unicorn)
+endif ()

pack/display/CMakeLists.txt

@@ -1,15 +1,3 @@
-cmake_minimum_required(VERSION 3.12)
-
-# Pull in PICO SDK (must be before project)
-include(pico_sdk_import.cmake)
-
-project(pico_examples C CXX ASM)
-set(CMAKE_C_STANDARD 11)
-set(CMAKE_CXX_STANDARD 17)
-
-# Initialize the SDK
-pico_sdk_init()
-
 add_executable(
   display
   demo.cpp
@@ -23,4 +11,4 @@ add_executable(
 target_link_libraries(display pico_stdlib hardware_spi hardware_pwm hardware_dma)
 
 # create map/bin/hex file etc.
-pico_add_extra_outputs(display)
+pico_add_extra_outputs(display)