fix issue with docs clearing the writeFn from the config. add complete embedding example to docs + repo

example/embedding/main.c

@@ -0,0 +1,45 @@
+//For more details, visit https://wren.io/embedding/
+
+#include <stdio.h>
+#include "wren.h"
+
+static void writeFn(WrenVM* vm, const char* text) {
+  printf("%s", text);
+}
+
+void errorFn(WrenVM* vm, WrenErrorType errorType, const char* module, const int line, const char* msg) {
+  switch (errorType) {
+    case WREN_ERROR_COMPILE: {
+      printf("[%s line %d] [Error] %s\n", module, line, msg);
+    } break;
+    case WREN_ERROR_STACK_TRACE: {
+      printf("[%s line %d] in %s\n", module, line, msg);
+    } break;
+    case WREN_ERROR_RUNTIME: {
+      printf("[Runtime Error] %s\n", msg);
+    } break;
+  }
+}
+
+int main() {
+
+  WrenConfiguration config;
+  wrenInitConfiguration(&config);
+    config.writeFn = &writeFn;
+    config.errorFn = &errorFn;
+  WrenVM* vm = wrenNewVM(&config);
+
+  const char* module = "main";
+  const char* script = "System.print(\"I am running in a VM!\")";
+
+  WrenInterpretResult result = wrenInterpret(vm, module, script);
+
+  switch (result) {
+    case WREN_RESULT_COMPILE_ERROR: { printf("Compile Error!\n"); } break;
+    case WREN_RESULT_RUNTIME_ERROR: { printf("Runtime Error!\n"); } break;
+    case WREN_RESULT_SUCCESS:       { printf("Success!\n");       } break;
+  }
+
+  wrenFreeVM(vm);
+
+}