Update Docker install docs with volume mount for registry files (#37043…

…) (#37049)

(cherry picked from commit ffbac9a)

Co-authored-by: David Kilfoyle <41695641+kilfoyle@users.noreply.github.com>

libbeat/docs/shared-docker.asciidoc

@@ -167,6 +167,7 @@ docker run -d \
   --volume="$(pwd)/{beatname_lc}.docker.yml:/usr/share/{beatname_lc}/{beatname_lc}.yml:ro" \
   --volume="/var/lib/docker/containers:/var/lib/docker/containers:ro" \
   --volume="/var/run/docker.sock:/var/run/docker.sock:ro" \
+  --volume="registry:/usr/share/{beatname_lc}/data:rw \  
   {dockerimage} {beatname_lc} -e --strict.perms=false \
   -E output.elasticsearch.hosts=["elasticsearch:9200"] <1> <2>
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