docs, tailscale: update tailnet field (#557)

Updates tailnet field to use tailnet ID (or legacy ID) instead of organization

Fixes #556

Signed-off-by: nikiUppal-TS <[email protected]>

Author: nikiUppal-TS

docs/index.md

@@ -37,5 +37,5 @@ provider "tailscale" {
 - `oauth_client_id` (String) The OAuth application's ID when using OAuth client credentials. Can be set via the TAILSCALE_OAUTH_CLIENT_ID environment variable. Both 'oauth_client_id' and 'oauth_client_secret' must be set. Conflicts with 'api_key'.
 - `oauth_client_secret` (String, Sensitive) The OAuth application's secret when using OAuth client credentials. Can be set via the TAILSCALE_OAUTH_CLIENT_SECRET environment variable. Both 'oauth_client_id' and 'oauth_client_secret' must be set. Conflicts with 'api_key'.
 - `scopes` (List of String) The OAuth 2.0 scopes to request when for the access token generated using the supplied OAuth client credentials. See https://tailscale.com/kb/1215/oauth-clients/#scopes for available scopes. Only valid when both 'oauth_client_id' and 'oauth_client_secret' are set.
-- `tailnet` (String) The organization name of the Tailnet in which to perform actions. Can be set via the TAILSCALE_TAILNET environment variable. Default is the tailnet that owns API credentials passed to the provider.
+- `tailnet` (String) The tailnet ID. Tailnets created before Oct 2025 can still use the legacy ID, but the Tailnet ID is the preferred identifier. Can be set via the TAILSCALE_TAILNET environment variable. Default is the tailnet that owns API credentials passed to the provider.
 - `user_agent` (String) User-Agent header for API requests.

tailscale/provider.go

@@ -65,7 +65,7 @@ func Provider(options ...ProviderOption) *schema.Provider {
 				Type:        schema.TypeString,
 				DefaultFunc: schema.EnvDefaultFunc("TAILSCALE_TAILNET", "-"),
 				Optional:    true,
-				Description: "The organization name of the Tailnet in which to perform actions. Can be set via the TAILSCALE_TAILNET environment variable. Default is the tailnet that owns API credentials passed to the provider.",
+				Description: "The tailnet ID. Tailnets created before Oct 2025 can still use the legacy ID, but the Tailnet ID is the preferred identifier. Can be set via the TAILSCALE_TAILNET environment variable. Default is the tailnet that owns API credentials passed to the provider.",
 			},
 			"base_url": {
 				Type:        schema.TypeString,