Fix kv value not identifying negative numbers in highlighter

Author: StefanH-AT

src/language/LangKv.ts

@@ -43,7 +43,7 @@ export class KeyvalueSemanticTokensProvider extends KvTokensProviderBase {
     protected keyProcessors: KvSemanticProcessor[] = [];
     protected valueProcessors: KvSemanticProcessor[] =
     [
-        { regex: /^\d+(\.\d+)?$/, processor: this.processValueNumber },
+        { regex: /^-?\d+(\.\d+)?$/, processor: this.processValueNumber },
         { regex: matrixRegExp, processor: this.processValueArray }
     ];