docs: add Tink API doc links to every method in client.py

src/tink/client.py

@@ -1,6 +1,9 @@
 """
 Tink API client — async httpx wrapper covering auth, users,
 accounts (v2), transactions (v2), events (v2), and bank connectivity.
+
+Tink API reference: https://docs.tink.com/api-introduction
+Endpoint reference: https://docs.tink.com/api#overview
 """
 
 import json
@@ -89,7 +92,10 @@ class TinkClient:
     # -------------------------------------------------------------------------
 
     async def get_app_token(self, scope: str = "user:create") -> dict:
-        """Client credentials flow — returns app-level token."""
+        """
+        Client credentials flow — returns app-level access token.
+        Docs: https://docs.tink.com/api#connectivity/oauth/create-an-oauth-token
+        """
         return await self._post(
             f"{self.api_base}/api/v1/oauth/token",
             headers={"Content-Type": "application/x-www-form-urlencoded"},
@@ -103,6 +109,10 @@ class TinkClient:
 
     async def exchange_code_for_token(self, code: str,
                                       redirect_uri: str | None = None) -> dict:
+        """
+        Exchange the authorization_code from Tink Link callback for a user-scoped token.
+        Docs: https://docs.tink.com/api#connectivity/oauth/create-an-oauth-token
+        """
         data: dict = {
             "client_id": self.client_id,
             "client_secret": self.client_secret,
@@ -123,6 +133,11 @@ class TinkClient:
 
     async def create_user(self, app_token: str, external_user_id: str,
                           market: str = "DK", locale: str = "da_DK") -> dict:
+        """
+        Create a Tink user linked to your internal customer reference.
+        external_user_id = your system's reference (e.g. "moneycapp-42"). Tink returns a user_id.
+        Docs: https://docs.tink.com/api#user/create-user
+        """
         return await self._post(
             f"{self.api_base}/api/v1/user/create",
             headers={"Authorization": f"Bearer {app_token}"},
@@ -137,6 +152,11 @@ class TinkClient:
 
     async def get_authorization_grant_token(self, app_token: str, user_id: str,
                                              scope: str) -> dict:
+        """
+        Delegate an authorization grant for a specific user — generates a one-time code
+        that binds the Tink Link session to that user.
+        Docs: https://docs.tink.com/api#connectivity/oauth/create-authorization
+        """
         return await self._post(
             f"{self.api_base}/api/v1/oauth/authorization-grant/delegate",
             headers={
@@ -153,6 +173,12 @@ class TinkClient:
     def get_tink_link_url(self, market: str = "DK",
                           authorization_code: str | None = None,
                           redirect_uri_override: str | None = None) -> str:
+        """
+        Build the Tink Link URL for bank connection.
+        With authorization_code: links the session to a specific Tink user (production flow).
+        Without: anonymous flow (sandbox only).
+        Docs: https://docs.tink.com/resources/tink-link/tink-link-web-permanent-users
+        """
         from urllib.parse import urlencode
         params: dict = {
             "client_id": self.client_id,
@@ -184,6 +210,10 @@ class TinkClient:
 
     async def list_accounts(self, user_token: str, page_size: int = 50,
                             page_token: Optional[str] = None) -> dict:
+        """
+        List all accounts for a user including balance and IBAN.
+        Docs: https://docs.tink.com/api#account-service-v2/account/list-accounts
+        """
         params: dict = {"pageSize": page_size}
         if page_token:
             params["pageToken"] = page_token
@@ -206,6 +236,10 @@ class TinkClient:
     async def list_transactions(self, user_token: str, page_size: int = 25,
                                 page_token: Optional[str] = None,
                                 account_id: Optional[str] = None) -> dict:
+        """
+        List transactions with cursor-based pagination.
+        Docs: https://docs.tink.com/api#transaction-service-v2/transaction/list-transactions
+        """
         params: dict = {"pageSize": page_size}
         if page_token:
             params["pageToken"] = page_token
@@ -265,6 +299,10 @@ class TinkClient:
 
     async def register_webhook(self, app_token: str, url: str,
                                 enabled_events: list[str] | None = None) -> dict:
+        """
+        Register a webhook endpoint for real-time transaction notifications.
+        Docs: https://docs.tink.com/api#webhook/create-webhook-endpoint
+        """
         return await self._post(
             f"{self.api_base}/api/v1/webhooks",
             headers={"Authorization": f"Bearer {app_token}"},