updated docs strings and added README.md

mail_intake/auth/__init__.py

@@ -1,31 +1,31 @@
 """
+# Summary
+
 Authentication provider implementations for Mail Intake.
 
----
-
-## Summary
-
 This package defines the **authentication layer** used by mail adapters
 to obtain provider-specific credentials.
 
 It exposes:
-- A stable, provider-agnostic authentication contract
-- Concrete authentication providers for supported platforms
+
+- A stable, provider-agnostic authentication contract.
+- Concrete authentication providers for supported platforms.
 
 Authentication providers:
-- Are responsible for credential acquisition and lifecycle management
-- Are intentionally decoupled from adapter logic
-- May be extended by users to support additional providers
+
+- Are responsible for credential acquisition and lifecycle management.
+- Are intentionally decoupled from adapter logic.
+- May be extended by users to support additional providers.
 
 Consumers should depend on the abstract interface and use concrete
 implementations only where explicitly required.
 
 ---
 
-## Public API
+# Public API
 
-    MailIntakeAuthProvider
-    MailIntakeGoogleAuth
+- `MailIntakeAuthProvider`
+- `MailIntakeGoogleAuth`
 
 ---
 """