a Bash script to generate docset for Zeal from a group of gems

docset_for_gem.sh

#!/bin/bash

# rubygem is required
# yard is required: gem install yard
# doc_to_dash is required: gem install doc_to_dash

GEM_NAME_PREFIX=$1
DOCSET_DIR=$2
TMP_DIR=$(mktemp -d)

for GEM_NAME in $(gem search --local $GEM_NAME_PREFIX | sed -e "/^$/d" -e "s/ \(.*\)$//"); do
  GEM_DIR=$(find $GEM_HOME -type d -name "$GEM_NAME-[0-9]*" | grep $GEM_NAME_PREFIX | sort -r | head -1)
  mkdir -p $TMP_DIR/$GEM_NAME
  yardoc --title $GEM_NAME --readme --protected --private --embed-mixins --output-dir $TMP_DIR/$GEM_NAME $GEM_DIR
  doc_to_dash -n $GEM_NAME -i $GEM_NAME_PREFIX.png -o $DOCSET_DIR $TMP_DIR/$GEM_NAME
  cat <<EOF > $DOCSET_DIR/$GEM_NAME.docset/meta.json
{
  "name": "$GEM_NAME",
  "title": "$GEM_NAME"
}
EOF
done

rm -Rv $TMP_DIR

can you provide some details on how to use this shell script and how to add in zeal aftewards?