Update readme with example

README.md

@@ -23,7 +23,7 @@ gem 'grape-middleware-logger'
 ## Usage
 ```ruby
 class API < Grape::API
-  # @note Make sure this above you're first +mount+
+  # @note Make sure this is above you're first +mount+
   use Grape::Middleware::Logger
 end
 ```
@@ -54,6 +54,15 @@ The middleware logger can be customized with the following options:
 * The `:logger` option can be any object that responds to `.info(String)`
 * The `:filter` option can be any object that responds to `.filter(Hash)` and returns a hash.
 
+For example:
+
+```ruby
+use Grape::Middleware::Logger, {
+  logger: Logger.new(STDERR),
+  filter: Class.new { def filter(opts) opts.reject { |k, _| k.to_s == 'password' } end }.new
+}
+```
+
 ## Using Rails?
 `Rails.logger` and `Rails.application.config.filter_parameters` will be used automatically as the default logger and 
 param filterer, respectively. This behavior can be overridden by passing the `:logger` or