Update label for pl extension (#22)

Author: tschaub

fields.json

@@ -50,7 +50,7 @@
 		"landsat": "Landsat",
 		"msft": "Microsoft",
 		"openeo": "openEO",
-		"pl": "Planet Labs Inc.",
+		"pl": "Planet Labs PBC",
 		"sentinel": "Copernicus Sentinel",
 		"cbers": {
 			"label": "CBERS",