revert filename and their contents as the default generated in idf.py create-project

Author: takasehideki

workspace/echoback_string/CMakeLists.txt

@@ -2,8 +2,8 @@
 # CMakeLists in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.16)
 
-set(EXTRA_COMPONENT_DIRS ../../ ../../platform)
+set(EXTRA_COMPONENT_DIRS ../..)
 add_compile_options(-w)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
-project(echoback_string)
+project(echoback_string)

workspace/echoback_string/main/CMakeLists.txt

@@ -1,6 +1,3 @@
-# Please set filename of mros2 application in main/
-set(APP_SRCS "app.cpp")
-
-idf_component_register(SRCS ${APP_SRCS}
+idf_component_register(SRCS "echoback_string.cpp"
                     INCLUDE_DIRS "."
                     PRIV_REQUIRES "mros2-esp32")