README.md: fix link to mkosi.1 man page for versions 25 and above.

Signed-off-by: Marc Herbert <[email protected]>

Author: marc-hb

README.md

@@ -211,5 +211,7 @@ Fortunately, most mkosi versions are thoroughly documented and you can
 easily check the documentation of any version without installing anything.
 For versions 14 and before, use this syntax:
   https://github.com/systemd/mkosi/blob/v14/man/mkosi.1
-For versions 15 and above go to:
+For versions between 15 and 24 go to:
   https://github.com/systemd/mkosi/blob/v15/mkosi/resources/mkosi.md
+For versions 25 and above:
+  https://github.com/systemd/mkosi/blob/v25/mkosi/resources/man/mkosi.1.md