Document --with-node-modules flag (#1701)

README.md

@@ -161,6 +161,8 @@ prettier --single-quote --trailing-comma es5 --write "{app,__{tests,mocks}__}/**
 (Don't forget the quotes around the globs! The quotes make sure that Prettier
 expands the globs rather than your shell, for cross-platform usage.)
 
+Prettier CLI will ignore files located in `node_modules` directory. To opt-out from this behavior use `--with-node-modules` flag.
+
 In the future we will have better support for formatting whole projects.
 
 If you're worried that Prettier will change the correctness of your code, add `--debug-check` to the command.

bin/prettier.js

@@ -245,6 +245,7 @@ if (argv["help"] || (!filepatterns.length && !stdin)) {
       "                           The range will extend forwards to the end of the selected statement.\n" +
       "                           Defaults to Infinity.\n" +
       "  --no-color               Do not colorize error messages.\n" +
+      "  --with-node-modules      Process files inside `node_modules` directory.\n" +
       "  --version or -v          Print Prettier version.\n" +
       "\n"
   );