First start: create the config file and open the Config view

Without a config file arr-tui refused to start. It now creates an empty
one (private, with its directory) and opens the Config view. A service
with neither address nor key is "not configured", which validation
allows: its client returns ErrNotConfigured without a request, its
indicator stays grey, it is logged once as information, and its lists
say so instead of showing errors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019reK4DUGYqDUjniWYJvwUW

README.md

@@ -56,9 +56,11 @@ or build from a checkout (`make build`), or `make dist` for cross-compiled binar
 
 ## Configure
 
-Copy `config.example.json` to `$XDG_CONFIG_HOME/arr-tui/config.json` (usually
-`~/.config/arr-tui/config.json`), or pass `--config path`. API keys are in each app under
-Settings → General.
+Just start `arr-tui`: on the first start it creates `$XDG_CONFIG_HOME/arr-tui/config.json`
+(usually `~/.config/arr-tui/config.json`, or the file given with `--config path`) and opens the
+Config view (F6), where you enter the address and API key of each service and save. API keys are in
+each app under Settings → General. A service left empty is not used (e.g. no SABnzbd), its indicator
+stays grey. You can also write the file yourself, starting from `config.example.json`:
 
 ```json
 {