Add documentation to the mariadb add-on (home-assistant#809)

* Update nginx_proxy add-on to use Bashio

Closes home-assistant#731

* Fixing shellcheck issues.

* Rev version number

* Use bashio::config.true where needed

* Add documentation to the mariadb add-on

fixes home-assistant#728

mariadb/README.md

@@ -0,0 +1,134 @@
+# Hass.io Core Add-on: MariaDB
+
+MariaDB database for Home Assistant.
+
+![Supports aarch64 Architecture][aarch64-shield] ![Supports amd64 Architecture][amd64-shield] ![Supports armhf Architecture][armhf-shield] ![Supports armv7 Architecture][armv7-shield] ![Supports i386 Architecture][i386-shield]
+
+## About
+
+You can use this add-on to install MariaDB, which is an open-source (GPLv2 licensed) database.  MariaDB can be used as the database backend for Home Assistant. For more information, please see [MariaDB][mariadb]
+
+## Installation
+
+The installation of this add-on is straightforward and easy to do.
+
+1. Navigate in your Home Assistant frontend to **Hass.io** -> **Add-on Store**.
+1. Find the "MariaDB" add-on and click it.
+1. Click on the "INSTALL" button.
+
+## How to use
+
+1. Set the `logins` -> `password` field to something strong and unique.
+1. Start the add-on.
+1. Check the add-on log output to see the result.
+1. Add `recorder` component to your Home Assistnat configuration.
+
+## Add-on Configuration
+
+The MariaDB server add-on can be tweaked to your likings. This section
+describes each of the add-on configuration options.
+
+Example add-on configuration:
+
+```json
+{
+  "databases": [
+    "homeassistant"
+  ],
+  "logins": [
+    {
+      "username": "hass",
+      "host": "%",
+      "password": null
+    }
+  ],
+  "rights": [
+    {
+      "username": "hass",
+      "host": "%",
+      "database": "homeassistant",
+      "grant": "ALL PRIVILEGES ON"
+    }
+  ]
+}
+```
+
+### Option: `databases` (required)
+
+Database name, e.g., `homeassistant`
+
+### Option: `logins` (required)
+
+This section defines a create user definition in MariaDB. [Create User][createuser] documentation.
+
+### Option: `logins` -> `username` (required)
+
+Database user login, e.g., `hass`. [User Name][username] documentation.
+
+### Option: `logins` -> `host` (required)
+
+Hostname allowed to connect to database. [Host Name][hostname] documentation.
+
+### Option: `logins` -> `password` (required)
+
+Password for user login. This should be strong and unique.
+
+### Option: `rights` (required)
+
+This section grant privileges to users in MariaDB. [Grant][grant] documentation.
+
+### Option: `rights` -> `username` (required)
+
+This should be the same user name defined in `logins` -> `username`.
+
+### Option: `rights` -> `host` (required)
+
+This should be the same hostname defined in `logins` -> `host`.
+
+### Option: `rights` -> `database` (required)
+
+This should be the same database defined in `databases`.
+
+### Option: `rights` -> `grant` (required)
+
+This is the grant statement giving your user access to the databse.
+
+## Home Assistant Configuration
+
+MariaDB will be used by the `recorder` and `history` components within Home Assistant.  For more information about setting this up, see the [MariaDB][mariadb-hass] documentation for Home Assistant. 
+
+Example Home Assistant configuration:
+
+```json
+recorder:
+  db_url: mysql://hass:password@core-mariadb/homeassistant?charset=utf8
+```
+
+## Support
+
+Got questions?
+
+You have several options to get them answered:
+
+- The [Home Assistant Discord Chat Server][discord].
+- The Home Assistant [Community Forum][forum].
+- Join the [Reddit subreddit][reddit] in [/r/homeassistant][reddit]
+
+In case you've found an bug, please [open an issue on our GitHub][issue].
+
+[aarch64-shield]: https://img.shields.io/badge/aarch64-yes-green.svg
+[amd64-shield]: https://img.shields.io/badge/amd64-yes-green.svg
+[armhf-shield]: https://img.shields.io/badge/armhf-yes-green.svg
+[armv7-shield]: https://img.shields.io/badge/armv7-yes-green.svg
+[mariadb]: https://mariadb.com
+[createuser]: https://mariadb.com/kb/en/library/create-user
+[username]: https://mariadb.com/kb/en/library/create-user/#user-name-component
+[hostname]: https://mariadb.com/kb/en/library/create-user/#host-name-component
+[grant]: https://mariadb.com/kb/en/library/grant
+[mariadb-hass]: https://www.home-assistant.io/addons/mariadb
+[discord]: https://discord.gg/c5DvZ4e
+[forum]: https://community.home-assistant.io
+[i386-shield]: https://img.shields.io/badge/i386-yes-green.svg
+[issue]: https://github.com/home-assistant/hassio-addons/issues
+[reddit]: https://reddit.com/r/homeassistant
+[repository]: https://github.com/hassio-addons/repository