Bump version number to 2.1.0

A version 2.0.5 has also been released a few months ago, but apparently
wasn't committed.

package-lock.json

 {
 	"name": "b-language-extension",
-	"version": "2.0.4",
+	"version": "2.1.0",
 	"lockfileVersion": 3,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "b-language-extension",
-			"version": "2.0.4",
+			"version": "2.1.0",
 			"license": "EPL-2.0",
 			"dependencies": {
 				"@types/ndjson": "^1.5.0",

package.json

@@ -2,7 +2,7 @@
 	"name": "b-language-extension",
 	"displayName": "B/ProB Language Support",
 	"description": "Compiler and language support for B via ProB",
-	"version": "2.0.4",
+	"version": "2.1.0",
 	"publisher": "SeeBasTStick",
 	"icon": "media/prob2-ui.png",
 	"author": "Sebastian Stock",