Add a demo code for PicoCalc

Code/picocalc_helloworld/i2ckbd/CMakeLists.txt

@@ -0,0 +1,20 @@
+# Generated Cmake Pico project file
+
+cmake_minimum_required(VERSION 3.13)
+
+set(CMAKE_C_STANDARD 11)
+
+project(i2ckbd
+        VERSION 0.0.1
+        DESCRIPTION "i2ckbd for picocalc."
+        )
+
+add_library(i2ckbd INTERFACE)
+
+target_sources(i2ckbd INTERFACE
+        i2ckbd.c
+        )
+
+target_link_libraries(i2ckbd INTERFACE  pico_stdlib hardware_spi hardware_i2c)
+
+target_include_directories(i2ckbd INTERFACE ${CMAKE_CURRENT_LIST_DIR})