Update links in wasi-sockets documentation to point to WASI (#883) (#852)

Author: wingo

proposals/filesystem/wit-0.3.0-draft/types.wit

@@ -595,9 +595,14 @@ interface types {
 
         /// Unlink a filesystem object that is not a directory.
         ///
-        /// Return `error-code::is-directory` if the path refers to a directory.
-        /// Note: This is similar to `unlinkat(fd, path, 0)` in POSIX.
-        @since(version = 0.3.0-rc-2026-02-09)
+        /// This is similar to `unlinkat(fd, path, 0)` in POSIX.
+        ///
+        /// Error returns are as specified by POSIX.
+        ///
+        /// If the filesystem object is a directory, `error-code::access` or
+        /// `error-code::is-directory` may be returned instead of the
+        /// POSIX-specified `error-code::not-permitted`.
+        @since(version = 0.3.0-rc-2025-02-09)
         unlink-file-at: async func(
             /// The relative path to a file to unlink.
             path: string,