Add My Home Assistant repository button to all addon READMEs

Add the "Add repository to my Home Assistant" blue button to all
addon README files that were missing it. This makes it easier for
new HA users to add the repository with a single click.

Updated 59 addon READMEs:
- 51 with standard Installation section format
- 8 with non-standard or missing Installation sections

Co-authored-by: alexbelgium <44178713+alexbelgium@users.noreply.github.com>

manyfold/README.md

@@ -21,16 +21,16 @@ Documentation: [manyfold.app/get-started](https://manyfold.app/get-started/)
 
 ## Installation
 
-1. In Home Assistant OS Add-on Store, open menu (`...`) -> `Repositories`.
-2. Add the Git repository URL for this add-on repository root (the repo includes `repository.yaml` and `manyfold/`).
-3. Refresh Add-on Store and install **Manyfold**.
-4. Configure options (defaults are safe for first run):
+1. Add my add-ons repository to your home assistant instance (in supervisor addons store at top right, or click button below if you have configured my HA)
+   [![Open your Home Assistant instance and show the add add-on repository dialog with a specific repository URL pre-filled.](https://my.home-assistant.io/badges/supervisor_add_addon_repository.svg)](https://my.home-assistant.io/redirect/supervisor_add_addon_repository/?repository_url=https%3A%2F%2Fgithub.com%2Falexbelgium%2Fhassio-addons)
+2. Refresh Add-on Store and install **Manyfold**.
+3. Configure options (defaults are safe for first run):
    - `library_path`: `/share/manyfold/models`
    - `secret_key_base`: leave blank to auto-generate
    - `puid` / `pgid`: set to a non-root UID/GID (see "Fix root warning (PUID/PGID)" below)
    - optionally tune worker/thread and upload limits in "Small server tuning" below
-5. Start the add-on.
-6. Open `http://<HA_IP>:3214`.
+4. Start the add-on.
+5. Open `http://<HA_IP>:3214`.
 
 Before first start, ensure your library folder exists on the host: