Update readme config examples

README.md

@@ -32,12 +32,37 @@ u.member_of_ldap_group?(['Some-Group'])
 
 ## Configuration
 
-Create a file `config/ldap_groups_lookup.yml` that looks like:
+### Initializer
+Create an initializer `config/initializers/ldap_groups_lookup.rb` that looks like:
+```ruby
+LDAPGroupsLookup.config = {
+  enabled: true,
+  config: { host: 'ads.example.net',
+            port: 636,
+            encryption: {
+              method: :simple_tls,
+              tls_options: OpenSSL::SSL::SSLContext::DEFAULT_PARAMS,
+            },
+            auth: {
+              method: :simple,
+              username: "cn=example",
+              password: 'changeme',
+            }
+  },
+  tree: 'dc=ads,dc=example,dc=net',
+  account_ou: 'ou=Accounts',
+  group_ou: 'ou=Groups',
+  member_whitelist: ['OU=Groups']
+}
+```
+
+### YAML
+Alternatively, create a file `config/ldap_groups_lookup.yml` that looks like:
 
 ```yaml
 :enabled: true
 :host: ads.example.net
-:port: 636
+:port: 389
 :auth:
   :method: :simple
   :username: example
@@ -47,4 +72,5 @@ Create a file `config/ldap_groups_lookup.yml` that looks like:
 :group_ou: ou=Groups
 :member_whitelist:
   - OU=Groups
-```
+```
+Note: The yaml style does not allow for easy configuration of some properties like tls_options or other auth methods.