fix: typo in uidmap option doc

The following section describes how to map to host ID `1`, not `1000`

Signed-off-by: Sola <dev@sola.love>

Author: unlimitedsola

docs/source/markdown/options/uidmap.container.md

@@ -109,7 +109,7 @@ regardless of how the intermediate mapping is defined.
 
 Some mapping modifications may be cumbersome. For instance, a user
 starts with a mapping such as `--gidmap="0:0:65000"`, that needs to be
-changed such as the parent id `1000` is mapped to container id `100000`
+changed such as the parent id `1` is mapped to container id `100000`
 instead, leaving container id `1` unassigned. The corresponding `--gidmap`
 becomes `--gidmap="0:0:1" --gidmap="2:2:65534" --gidmap="100000:1:1"`.