Merge pull request braziljs#391 from heversonr/correcaoCap10

Adiciona correção no Capítulo 10 linhas 246,247

Author: joaostein

chapters/10-modulos.md

@@ -240,8 +240,8 @@ function require(name) {
     return require.cache[name];
 
   var code = new Function("exports, module", readFile(name));
-  var exports = {}, mod = {exports: exports};
-  code(exports, mod);
+  var exports = {}, module = {exports: exports};
+  code(exports, module);
 
   require.cache[name] = module.exports;
   return module.exports;