community.md - missing instances

[pmauduit]

Another georchestra instance which is not listed:

https://data.za-seine.fr/geonetwork/srv/fre/csw

[fvanderbiest]

Some cleanup :

• Vienne Condrieu is not using geOrchestra anymore

Additions to be done :

• Biotope https://www.biotope.fr/ in "Companies"
• CBNBL https://georchestra.cbnbl.org/
• Dreal Corsica https://georchestra.ac-corse.fr/
• GeoRhena https://geoportal.georhena.eu/
• Isère department (private url)
• St Dizier https://data.agglo-saintdizier.fr/