docs: Update introduction.rst

Corrected the sentence (more one or more)

docs/socialaccount/introduction.rst

@@ -3,7 +3,7 @@ Introduction
 
 A social account is a user account where authentication is delegated to an external identity provider. The ``allauth.socialaccount`` app is responsible for managing social accounts. It supports:
 
-- Connecting more one or more social accounts to a local/regular account
+- Connecting one or more social accounts to a local/regular account
 
 - Disconnecting a social account -- requires setting a password if
   only the local account remains