Add Facebook social login

public/lang/en/auth.json

@@ -61,6 +61,8 @@
     "oauth_divider": "or",
     "google_cta": "Continue with Google",
     "google_helper": "Use your Google account to access the event dashboard securely.",
+    "facebook_cta": "Continue with Facebook",
+    "facebook_helper": "Use your Facebook account to access the event dashboard securely.",
     "no_account": "Don't have access yet?",
     "sign_up": "Create an account"
   },

public/lang/en/marketing.json

@@ -645,11 +645,17 @@
       "switch_to_register": "Register",
       "switch_to_login": "Login",
       "continue_with_google": "Continue with Google",
+      "continue_with_facebook": "Continue with Facebook",
       "google_success_toast": "Signed in with Google.",
       "google_error_title": "Google login failed",
       "google_missing_package": "Please choose a package before using Google login.",
       "google_missing_email": "We could not retrieve your Google email address.",
       "google_error_fallback": "We couldn't complete the Google login. Please try again.",
+      "facebook_success_toast": "Signed in with Facebook.",
+      "facebook_error_title": "Facebook login failed",
+      "facebook_missing_package": "Please choose a package before using Facebook login.",
+      "facebook_missing_email": "We could not retrieve your Facebook email address.",
+      "facebook_error_fallback": "We couldn't complete the Facebook login. Please try again.",
       "google_helper": "Sign in faster with Google – we only use your details to create your Fotospiel account.",
       "google_helper_badge": "Why Google?"
     },