Release v0.8.0 — Portainer-first install, in-app guide

- Install from Portainer with no command line: paste the compose, set a
  folder and a password, deploy. Inspector creates its own config and
  detects Docker socket permissions by itself.
- Illustrated how-to guide inside the app (Help tab) and in the repo.
- Containers added in the UI are watched right away, no restart.
- maintenance_window switch on the container form.
- README with logo and screenshots; INSTALL rewritten for Portainer.

config.example.yml

@@ -1,5 +1,9 @@
-# Inspector example configuration.
-# Copy to config.yml, edit, and mount into the container at /app/config.yml.
+# Inspector example configuration: every option, with comments.
+#
+# You normally don't need this file. Inspector writes its own config.yml to
+# INSPECTOR_DATA/config/ on first start, and the dashboard edits it for you.
+# Use this as a reference for the advanced options that are YAML-only
+# (http_check, uptime_kuma, depends_on, Portainer stack redeploy).
 
 inspector:
   interval_seconds: 60