DOC: Retest substitutions [skip ci]

Author: mgxd

docs/usage.md

@@ -86,11 +86,11 @@ For installation instructions, please see [](installation.md#installing-the-niba
 ### Sample Docker usage
 
 ```
-$ nibabies-wrapper docker /path/to/data /path/to/output participant --age-months 12 --fs-license-file /usr/freesurfer/license.txt
+$ nibabies-wrapper docker /path/to/data /path/to/output participant --fs-license-file /usr/freesurfer/license.txt
 
 RUNNING: docker run --rm -e DOCKER_VERSION_8395080871=20.10.6 -it -v /path/to/data:/data:ro \
 -v /path/to/output:/out -v /usr/freesurfer/license.txt:/opt/freesurfer/license.txt:ro \
-nipreps/nibabies:21.0.0 /data /out participant --age-months 12
+nipreps/nibabies:{{version}} /data /out participant
 ...
 ```
 
@@ -104,11 +104,11 @@ This can be overridden by using the `-i` flag to specify a particular Docker ima
 ### Sample Singularity usage
 
 ```
-$ nibabies-wrapper singularity /path/to/data /path/to/output participant --age-months 12 -i nibabies-21.0.0.sif --fs-license-file /usr/freesurfer/license.txt
+$ nibabies-wrapper singularity /path/to/data /path/to/output participant -i nibabies-{{version}}.sif --fs-license-file /usr/freesurfer/license.txt
 
 RUNNING: singularity run --cleanenv -B /path/to/data:/data:ro \
 -B /path/to/output:/out -B /usr/freesurfer/license.txt:/opt/freesurfer/license.txt:ro \
-nibabies-21.0.0.sif /data /out participant --age-months 12
+nibabies-{{version}}.sif /data /out participant
 ...
 ```