update secrets reference (#120)

Author: octref

modus/app-manifest.mdx

@@ -188,8 +188,8 @@ Typically, you'll use the `baseUrl` field. However, some APIs, such as
 If provided, requests on the connection include these headers. Each key-value pair is a header name and value.
 
 Values may include variables using the `{{VARIABLE}}` template syntax, which
-resolve at runtime to secrets provided for each connection, via the Hypermode
-Console.
+resolve at runtime to environment variables provided for each connection, via
+the Hypermode Console.
 
   <Accordion title="Examples">