Add submodule init and update to cmake

CMakeLists.txt

@@ -153,6 +153,15 @@ else()
   message(STATUS "Building without build tag")
 endif()
 
+# Update and init submodules by default
+if(NOT MANUAL_SUBMODULES)
+  find_package(Git)
+  if(GIT_FOUND)
+    message(STATUS "Initializing submodules")
+    execute_process(COMMAND git "submodule" "update" "--init" "--recursive" WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
+  endif()
+endif()
+
 set(CMAKE_C_FLAGS_RELEASE "-DNDEBUG ${OPT_FLAGS_RELEASE}")
 set(CMAKE_CXX_FLAGS_RELEASE "-DNDEBUG ${OPT_FLAGS_RELEASE}")
 

README.md

@@ -135,13 +135,10 @@ build the library binary manually. This can be done with the following command `
 
 ### Cloning the repository
 
-Clone recursively to pull-in needed submodule(s):
+`$ git clone https://github.com/wownero/wownero`
 
-`$ git clone --recursive https://github.com/wownero/wownero`
-
-If you already have a repo cloned, initialize and update:
-
-`$ cd wownero && git submodule init && git submodule update`
+Submodules are fetched and updated automatically. If you wish to
+do this manually, run CMake flag `-DMANUAL_SUBMODULES=ON` to opt out.
 
 ### Build instructions