Work out file reading and writing

processor/regex.go

@@ -90,11 +90,6 @@ type CaptureGroup struct {
 	Updated string
 	Range   [2]int
 }
-type ReplaceCommand struct {
-	From int
-	To   int
-	With string
-}
 
 // ProcessContent applies regex replacement with Lua processing
 func (p *RegexProcessor) ProcessContent(content string, pattern string, luaExpr string) (string, int, int, error) {