Explain why unminimization script is a bit complicated

live-build/auto/build

@@ -89,8 +89,13 @@ if [ -f /etc/dpkg/dpkg.cfg.d/excludes ] || [ -f /etc/dpkg/dpkg.cfg.d/excludes.dp
     apt-get upgrade
     echo "Restoring system documentation..."
     echo "Reinstalling packages with files in /usr/share/man/ ..."
+    # Reinstallation takes place in two steps because a single dpkg --verified
+    # command generates very long parameter list for "xargs dpkg -S" and may go
+    # over ARG_MAX. Since many packages have man pages the second download
+    # handles a much smaller amount of packages.
     dpkg -S /usr/share/man/ |sed 's|, |\n|g;s|: [^:]*$||' | DEBIAN_FRONTEND=noninteractive xargs apt-get install --reinstall -y
     echo "Reinstalling packages with system documentation in /usr/share/doc/ .."
+    # This step processes the packages which still have missing documentation
     dpkg --verify --verify-format rpm | awk '/..5......   \/usr\/share\/doc/ {print $2}' | sed 's|/[^/]*$||' | sort |uniq \
          | xargs dpkg -S | sed 's|, |\n|g;s|: [^:]*$||' | uniq | DEBIAN_FRONTEND=noninteractive xargs apt-get install --reinstall -y
     if dpkg --verify --verify-format rpm | awk '/..5......   \/usr\/share\/doc/ {exit 1}'; then