copy over docs from the wrong repo; take out error/warning wrappers

samples/node_errors/node_errors.c

@@ -19,7 +19,7 @@ int main(int argument_count, char **arguments)
     {
         for(MD_EachNode(node, root->first_child))
         {
-            MD_NodeErrorF(node, "This node has an error!");
+            MD_NodeMessageF(node, MD_MessageKind_Error, "This node has an error!");
         }
     }