docs: mention CURLOPT_MAX_RECV/SEND_SPEED_LARGE don't work for FILE://

docs/libcurl/curl_easy_setopt.3

@@ -2229,12 +2229,18 @@ it too slow and abort.
 Pass a curl_off_t as parameter.  If an upload exceeds this speed (counted in
 bytes per second) on cumulative average during the transfer, the transfer will
 pause to keep the average rate less than or equal to the parameter value.
-Defaults to unlimited speed. (Added in 7.15.5)
+Defaults to unlimited speed.
+
+This option doesn't affect transfer speeds done with FILE:// URLs. (Added in
+ 7.15.5)
 .IP CURLOPT_MAX_RECV_SPEED_LARGE
 Pass a curl_off_t as parameter.  If a download exceeds this speed (counted in
 bytes per second) on cumulative average during the transfer, the transfer will
 pause to keep the average rate less than or equal to the parameter
-value. Defaults to unlimited speed. (Added in 7.15.5)
+value. Defaults to unlimited speed.
+
+This option doesn't affect transfer speeds done with FILE:// URLs. (Added in
+7.15.5)
 .IP CURLOPT_MAXCONNECTS
 Pass a long. The set number will be the persistent connection cache size. The
 set amount will be the maximum amount of simultaneously open connections that