docs(SimpleGrid): Avatar fix img alt text (#9124)

Author: SevereCloud

website/content/components/simple-grid.mdx

@@ -72,10 +72,10 @@ VKUI (например, [`Header`](/components/group#header) и [`SimpleCell`](/
   ```jsx
   <Group mode="card" header={<Header size="s">Друзья</Header>}>
     <SimpleGrid gap="m" columns={2} margin="auto">
-      <Avatar size={48} src="#" initials="ДС" gradientColor="orange" />
-      <Avatar size={48} src="#" initials="ИМ" gradientColor="yellow" />
-      <Avatar size={48} src="#" initials="ВЖ" gradientColor="violet" />
-      <Avatar size={48} src="#" initials="ЭМ" gradientColor="green" />
+      <Avatar size={48} initials="ДС" gradientColor="orange" />
+      <Avatar size={48} initials="ИМ" gradientColor="yellow" />
+      <Avatar size={48} initials="ВЖ" gradientColor="violet" />
+      <Avatar size={48} initials="ЭМ" gradientColor="green" />
     </SimpleGrid>
   </Group>
   ```