feat: allow flags to be specified per transformer

src/configuration.ts

@@ -23,6 +23,7 @@ export interface Category {
 export interface Transformer {
   pattern: string
   target: string
+  flags?: string
 }
 
 export interface Extractor extends Transformer {

src/transform.ts

@@ -247,7 +247,10 @@ function validateTransfomers(
         }
 
         return {
-          pattern: new RegExp(transformer.pattern.replace('\\\\', '\\'), 'gu'),
+          pattern: new RegExp(
+            transformer.pattern.replace('\\\\', '\\'),
+            transformer.flags ?? 'gu'
+          ),
           target: transformer.target,
           onProperty
         }