chore: remove code-server-lsio, collabora, onlyoffice and seafile

Drop the four service directories and their rows from the root index, and
replace code-server-lsio in the naming, workspace and environment rules with
a generic example.

code-server-lsio/.env.example

@@ -1,18 +0,0 @@
-# Copy to .env and fill in. Never commit .env.
-#
-#   cp .env.example .env
-
-# Container hostname, also passed in as HOST -- the name zsh's prompt shows.
-SERVICE_HOSTNAME=code-server-lsio
-
-# Web UI login password. Required.
-# Also used for SUDO_PASSWORD inside the container.
-# Generate one with: openssl rand -base64 24
-PASSWORD=
-
-# Git identity baked into the container (author + committer).
-GIT_NAME=
-GIT_EMAIL=
-
-# Name of the installed web app.
-# PWA_APPNAME=code-server