Docs: Fix 'file not found' errors

DOCS/package-format.txt

@@ -264,27 +264,27 @@ Meta Examples
 .A devel-only package
 [sh]
 source~~~~
-include::../packages/gmp/meta[]
+include::../packages/libs/gmp/meta[]
 source~~~~
 
 .A standard runtime package
 [sh]
 source~~~~
-include::../packages/lsof/meta[]
+include::../packages/utils/lsof/meta[]
 source~~~~
 Note the use of $TARGET_LIBC in PKG_DEPENDS to refer to the runtime system libc
 (which could be uClibc, glibc or eglibc)
 
 .A non-free package available only on selected archs
 [sh]
 source~~~~
-include::../packages/xf86-video-nvidia/meta[]
+include::../packages/x11/xf86-video-nvidia/meta[]
 source~~~~
 
 .A complex package which shows the usage of conditionals to define the depends
 [sh]
 source~~~~
-include::../packages/MPlayer/meta[]
+include::../packages/multimedia/MPlayer/meta[]
 source~~~~
 
 Package scripts