docs(readme): the configure menu, the apps table and the switch receiver

The Configure page is a menu of sub-screens now, the Apps row is an
editable one-row-per-app table, and a receiver may be a `switch.*`.

README.md

@@ -290,8 +290,57 @@ helper the flow calls is a coroutine and its dedup only runs when awaited.
 
 ### Options
 
+The Configure page is a **menu of sub-screens**, not one long form. Home Assistant
+renders it as a list of rows; each row opens a short form and comes back to the menu,
+and only **Save and close** commits:
+
+| Row | What it holds |
+| --- | --- |
+| **Main setup** | Shield address, ADB port, `Read state over ADB`, `Add the Nvidia Remote Protocol`, `Show title and artist`, `Allow the adb_command action`, Jellyfin player, power switch |
+| **Receiver** | the receiver/soundbar entity and the input it uses |
+| **Apps** | the apps table — one row per app (see below) |
+| **Scripts** | one optional script per command, plus the remote-entity script, the channel digit delay and send-ENTER |
+| **Save and close** | writes the merged options and reloads the integration |
+
+Every field that used to be on the single page is still there, under one of those
+rows. Edits are merged **per key**, so visiting another sub-screen (or saving from a
+later one) never drops what an earlier one changed. Half-finished pages are not
+written: closing the dialog without **Save and close** leaves the entry as it was.
+
+The **setup** flow follows the same shape: its first form is unchanged (name, host,
+transports, the linked entities), and after it the flow is a menu — Receiver /
+Connection / pairing rows / Create the entry — so anything you want to correct is one
+row away instead of buried in a form you have already submitted. The pairing rows
+appear only while a transport still needs pairing.
+
+### The Apps table
+
+The **Apps** row is an editable table. One app per line, in the documented format:
+
+```
+ar.tvplayer.tv=TiviMate
+com.plex.hdx=Plex|http://192.168.1.10:9000/plex.png
+com.netflix.ninja=Netflix
+```
+
+`package=name` is enough; an optional `|icon` after the name adds a picture (a URL, or
+a `camera.*` entity id — see *Sources* below). The field always opens carrying the
+current rows, so adding, renaming or deleting an app is an edit to that text:
+
+- **add a row** — type a new line
+- **edit a row** — change its name, icon or package id
+- **remove a row** — delete its line
+
+A blank field clears the table (and the integration falls back to its built-in app
+list). A malformed row — no `=`, or an empty name — is rejected with an error on the
+page rather than being half-saved.
+
+A receiver may be a **`switch.*`** as well as a `media_player.*`: a soundbar or
+speaker that only knows on and off is a valid receiver. (Driving that switch during
+playback is a separate, later change.)
+
 - **Jellyfin Media Player** — auto-detected or manually selected
-- **Receiver + Input** — for media-zone coordination
+- **Receiver + Input** — for media-zone coordination; `media_player` or `switch`
 - **Power Switch** — smart plug entity
 - **Read state over ADB / Add the Nvidia Remote Protocol** — turn either
   transport on or off