Adds a Troubleshooting entry (symptom, cause, drop-or-keep fixes). The keep path removes grml-zsh-config instead of setting skip_global_compinit=1: grml's /etc/zsh/zshrc runs compinit unconditionally and ignores that Debian/Ubuntu variable. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>