Reactのバージョンを18にする #1

# to view logs

	name: build on pr
	on: pull_request

	jobs:
	build:
	defaults:
	run:
	shell: bash
	working-directory: ./react-visualizer
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- name: Use Node.js
	uses: actions/setup-node@v4
	with:
	node-version: 20
	- uses: actions/cache@v4
	id: node_modules_cache_id
	env:
	cache-name: cache-node-modules
	with:
	path: '**/node_modules'
	key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
	- if: ${{ steps.node_modules_cache_id.outputs.cache-hit != 'true' }}
	run: npm install
	- name: Build
	run: \|
	npm run build

Provide feedback