README: clearer HACS install steps + early-access status callout

Adds a post-install "add via Devices & Services" step that users
frequently miss, tightens the HACS custom-repository wording, and
prepends a status note so HACS users know this is still 0.1.x.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -4,6 +4,8 @@
 
 Enhanced NVIDIA Shield TV integration for Home Assistant. ADB-based media session tracking, Jellyfin rich metadata, power monitoring, and receiver coordination.
 
+> **Status:** Early access (0.1.x). Tested on the author's own setup; expect rough edges and occasional breaking changes until 1.0. Please file issues on GitHub if anything is broken.
+
 ```mermaid
 graph TD
     subgraph "NVIDIA Shield Integration"
@@ -38,14 +40,15 @@ graph TD
 
 ### HACS (recommended)
 
-1. Open HACS > Integrations > three-dot menu > Custom repositories
+1. In HACS, open the overflow menu (⋮) → **Custom repositories**.
-2. Add `https://github.com/ltomes/ha-nvidia-shield` as an Integration
+2. Paste `https://github.com/ltomes/ha-nvidia-shield`, pick type **Integration**, click **Add**.
-3. Search for "NVIDIA Shield" and install
+3. Find **NVIDIA Shield** in the HACS list and click **Download**.
-4. Restart Home Assistant
+4. **Restart Home Assistant.**
+5. Go to **Settings → Devices & Services → Add Integration**, search for **NVIDIA Shield**, and set up the integration (see [Configuration](#configuration)).
 
 ### Manual
 
-Copy `custom_components/nvidia_shield` to your HA `config/custom_components/` directory and restart.
+Copy `custom_components/nvidia_shield` to your HA `config/custom_components/` directory, restart, then add the integration from **Settings → Devices & Services**.
 
 ## Configuration