Allow to set config with `.pronto_eslint_npm.yml`

Make configuration dependent on instance instead of class, too.

1 files changed, 22 insertions, 1 deletions

diff --git a/README.md b/README.md
index 4fb2cdc..9ee2e19 100644
--- a/README.md
+++ b/README.md
@@ -17,9 +17,30 @@ You'll need to install [eslint by yourself with npm][eslint-install].
 
 [eslint-install]: http://eslint.org/docs/user-guide/getting-started
 
-## Configuration
+## Configuration of ESLint
 
 Configuring ESLint via [.eslintrc and consorts][eslintrc] and excludes via [.eslintignore][eslintignore] will work just fine with pronto-eslint.
 
 [eslintrc]: http://eslint.org/docs/user-guide/configuring#configuration-file-formats
+
 [eslintignore]: http://eslint.org/docs/user-guide/configuring#ignoring-files-and-directories
+
+## Configuration of ESLintNPM
+
+Pronto::ESLintNPM can be configured by placing a `.pronto_eslint_npm.yml` inside the directory
+where pronto is run.
+
+Following options are available:
+
+| Option            | Meaning                                                                           | Default                             |
+| ----------------- | --------------------------------------------------------------------------------- | ----------------------------------- |
+| eslint_executable | ESLint executable to call                                                         | `eslint` (calls `eslint` in `PATH`) |
+| files_to_lint     | What files to lint. Absolute path of the file will be matched against this regexp | `(\.js|\.es6)$`                     |
+
+Example configuration to call custom eslint executable and only lint files ending with `.my_custom_extension`:
+
+```yaml
+# .pronto_eslint_npm.yaml
+eslint_executable: '/my/cusom/node/path/.bin/eslint'
+files_to_lint: '\.my_custom_extension$'
+```