Belgium: Update Capacities (electricitymaps#2404)

* Update zones.json

* removed outdated source

* Update README.md

* Capacity Update

* Updated Readme

Co-authored-by: Roberta Hunt <roberta.hunt@tmrow.com>
Co-authored-by: martincollignon <2604526+martincollignon@users.noreply.github.com>

README.md

@@ -214,8 +214,9 @@ Production capacities are centralized in the [zones.json](https://github.com/tmr
 - Bahrain: [IRENA](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Mar/IRENA_RE_Capacity_Statistics_2020.pdf)
 - Belarus: [belstat.gov.by](http://www.belstat.gov.by/upload/iblock/7f7/7f70938f51eb9e49abc4a6e62f831a2c.rar), [RenEn](http://director.by/zhurnal/arkhiv-zhurnala/arkhiv-nomerov-2017/375-7-2017-iyul-2017/5456-zelenaya-energetika-nabiraet-oboroty)
 - Belgium
-  - Hydro, Oil: [ENTSO-E](https://transparency.entsoe.eu/generation/r2/installedGenerationCapacityAggregation/show)
-  - Other: [ELIA](https://www.eliagroup.eu/-/media/project/elia/shared/documents/elia-group/publications-pdfs/20190411_gri18_elia_en.pdf)
+  - Solar: [IRENA](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Mar/IRENA_RE_Capacity_Statistics_2020.pdf)
+  - Hydro & Wind: [ELIA](https://www.elia.be/-/media/project/elia/shared/documents/elia-group/publications-pdfs/20200414_elia_annual-report-sustainability_en.pdf)
+  - Other: [ENTSO-E](https://transparency.entsoe.eu/generation/r2/installedGenerationCapacityAggregation/show)
 - Bolivia: [CNDC](http://www.cndc.bo/agentes/generacion.php)
 - Bosnia and Herzegovina: [ENTSO-E](https://transparency.entsoe.eu/generation/r2/installedGenerationCapacityAggregation/show)
 - Brazil: [ONS](http://www.ons.org.br/Paginas/resultados-da-operacao/historico-da-operacao/capacidade_instalada.aspx)

config/zones.json

@@ -462,19 +462,20 @@
       ]
     ],
     "capacity": {
-      "biomass": 1113,
+      "biomass": 1173,
       "coal": 0,
-      "gas": 6974,
+      "gas": 6777,
       "geothermal": 0,
-      "hydro": 181,
-      "hydro storage": 1308,
+      "hydro": 125,
+      "hydro storage": 1310,
       "nuclear": 5919,
-      "oil": 334,
-      "solar": 3581,
-      "wind": 3247
+      "oil": 341,
+      "solar": 4531,
+      "wind": 4037
     },
     "contributors": [
-      "https://github.com/corradio"
+      "https://github.com/corradio",
+      "https://github.com/nessie2013"
     ],
     "parsers": {
       "consumption": "ENTSOE.fetch_consumption",