Add titles for a better user experience (#137)

Co-authored-by: Mario Gómez <60667991+mgomezarr@users.noreply.github.com>

src/app/groups/[groupId]/expenses/page.tsx

@@ -51,6 +51,7 @@ export default async function GroupExpensesPage({
                 prefetch={false}
                 href={`/groups/${groupId}/expenses/export/json`}
                 target="_blank"
+                title="Export to JSON"
               >
                 <Download className="w-4 h-4" />
               </Link>
@@ -63,7 +64,10 @@ export default async function GroupExpensesPage({
               />
             )}
             <Button asChild size="icon">
-              <Link href={`/groups/${groupId}/expenses/create`}>
+              <Link
+                href={`/groups/${groupId}/expenses/create`}
+                title="Create expense"
+              >
                 <Plus className="w-4 h-4" />
               </Link>
             </Button>

src/app/groups/[groupId]/share-button.tsx

@@ -23,7 +23,7 @@ export function ShareButton({ group }: Props) {
   return (
     <Popover>
       <PopoverTrigger asChild>
-        <Button size="icon">
+        <Button title="Share" size="icon">
           <Share className="w-4 h-4" />
         </Button>
       </PopoverTrigger>