improve player spawning and esp-idf compatibility

src/CMakeLists.txt

@@ -0,0 +1,8 @@
+# This file is meant for use with ESP-IDF or PlatformIO.
+# Compilation for other platforms must be done manually.
+
+FILE(GLOB_RECURSE app_sources ${CMAKE_SOURCE_DIR}/src/*.*)
+
+idf_component_register(SRCS ${app_sources}
+  PRIV_REQUIRES esp_wifi nvs_flash
+  INCLUDE_DIRS ".")