fix: add missing React imports

src/components/atoms/Footer.tsx

@@ -1,4 +1,4 @@
-import { ReactNode } from "react"
+import React, { ReactNode } from "react"
 import { Box, useTheme } from "@mui/material"
 
 export type FooterProps = {

src/components/organisms/Layout.tsx

@@ -1,6 +1,6 @@
+import React, { ReactNode, useMemo } from "react"
 import { AppBar, Box, Button, Container, createTheme, CssBaseline, Link, ThemeProvider, Toolbar, Typography, useMediaQuery, useTheme } from "@mui/material"
 import CodeIcon from "@mui/icons-material/Code"
-import { ReactNode, useMemo } from "react"
 import { Link as GatsbyLink } from "gatsby"
 import { Footer } from "../atoms/Footer"
 

src/pages/404.tsx

@@ -1,4 +1,4 @@
-import * as React from "react"
+import React from "react"
 import { Link } from "gatsby"
 
 // styles

src/pages/blog/index.tsx

@@ -1,4 +1,4 @@
-import { ReactNode } from "react"
+import React, { ReactNode } from "react"
 import { GatsbyLinkProps, graphql, Link, PageProps } from "gatsby"
 import Layout from "../../components/organisms/Layout"
 import { Card, CardContent, CardMedia, Grid, Typography } from "@mui/material"

src/pages/index.tsx

@@ -1,3 +1,4 @@
+import React from "react"
 import styled from "@emotion/styled"
 import { Box, Card as Card_, CardContent, Grid, Typography } from "@mui/material"
 import {