Add EU EAQI

[ringsaturn]

1. https://environment.ec.europa.eu/topics/air_en
2. https://www.eea.europa.eu/highlights/european-air-quality-index-current
3. https://www.eea.europa.eu/themes/air/air-quality-index
4. https://www.eea.europa.eu/highlights/european-air-quality-index-current
5. https://airindex.eea.europa.eu/Map/AQI/Viewer/
6. Rules:

+------------------------------------+-------------------------------------------------------------------+
| Pollutant                          | Index level                                                       |
|                                    | (based on pollutant concentrations in µg/m3)                      |
|                                    +-------+---------+----------+---------+-----------+----------------+
|                                    | Good  | Fair    | Moderate | Poor    | Very poor | Extremely poor |
+====================================+=======+=========+==========+=========+===========+================+
| Particles less than 2.5 µm (PM2.5) | 0-10  | 10-20   | 20-25    | 25-50   | 50-75     | 75-800         |
+------------------------------------+-------+---------+----------+---------+-----------+----------------+
| Particles less than 10 µm (PM10)   | 0-20  | 20-40   | 40-50    | 50-100  | 100-150   | 150-1200       |
+------------------------------------+-------+---------+----------+---------+-----------+----------------+
| Nitrogen dioxide (NO2)             | 0-40  | 40-90   | 90-120   | 120-230 | 230-340   | 340-1000       |
+------------------------------------+-------+---------+----------+---------+-----------+----------------+
| Ozone (O3)                         | 0-50  | 50-100  | 100-130  | 130-240 | 240-380   | 380-800        |
+------------------------------------+-------+---------+----------+---------+-----------+----------------+
| Sulphur dioxide (SO2)              | 0-100 | 100-200 | 200-350  | 350-500 | 500-750   | 750-1250       |
+------------------------------------+-------+---------+----------+---------+-----------+----------------+