fix incorrect documentation for ldap providers (#408)

config.yml.sample

@@ -17,7 +17,6 @@ auth:
   ldap:
     - id: ldap1
       provider_name: company ldap
-      display_name: Login with</br>LDAP
       url: ldap://ldap.yourcompany.local:389
       bind_user: ldap_wireguard@yourcompany.local
       bind_pass: super_Secret_PASSWORD

docs/documentation/configuration/examples.md

@@ -43,7 +43,6 @@ auth:
     # a sample LDAP provider with user sync enabled
     - id: ldap
       provider_name: Active Directory
-      display_name: Login with</br>AD
       url: ldap://srv-ad1.company.local:389
       bind_user: ldap_wireguard@company.local
       bind_pass: super-s3cr3t-ldap

docs/documentation/configuration/overview.md

@@ -456,6 +456,10 @@ Below are the properties for each OAuth provider entry inside `auth.oauth`:
 The `ldap` array contains a list of LDAP authentication providers.
 Below are the properties for each LDAP provider entry inside `auth.ldap`:
 
+#### `provider_name`
+- **Default:** *(empty)*
+- **Description:** A **unique** name for this provider. Must not conflict with other providers.
+
 #### `url`
 - **Default:** *(empty)*
 - **Description:** The LDAP server URL (e.g., `ldap://srv-ad01.company.local:389`).