Add divider option to section header (#90)

lib/widgets/section_header.dart

@@ -4,25 +4,37 @@ class SectionHeader extends StatelessWidget {
   final String text;
   final EdgeInsets padding;
   final double? fontSize;
+  final bool showDivider;
 
   const SectionHeader(
     this.text, {
     Key? key,
     this.padding = const EdgeInsets.fromLTRB(10.0, 20.0, 10.0, 5.0),
     this.fontSize,
+    this.showDivider = false,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return Padding(
       padding: padding,
-      child: Text(
-        text.toUpperCase(),
-        style: TextStyle(
-          fontSize: fontSize,
-          fontWeight: FontWeight.w600,
-          letterSpacing: 0.8,
-        ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            text.toUpperCase(),
+            style: TextStyle(
+              fontSize: fontSize,
+              fontWeight: FontWeight.w600,
+              letterSpacing: 0.8,
+            ),
+          ),
+          if (showDivider)
+            const Divider(
+              height: 10.0,
+              thickness: 1.0,
+            ),
+        ],
       ),
     );
   }