~/.bin/archive-monthly.sh: Describe what the thing does

.bin/archive-monthly.sh

@@ -1,5 +1,8 @@
#!/bin/bash
# Archives hidden files in $HOME to a monthly directory that has
# backups.
TARGET="$HOME/d/history-$(date +%Y-%m)"
echo "Archiving files (and directories in) $PWD to $TARGET"