Add React 17 and npm 7 Support

[ChihweiLHBird]

PS C:\path\to\react_app> npm install -dev--save react-router-sitemap@latest
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! While resolving: shopping-ui-react-responsive@0.1.0
npm ERR! Found: react@17.0.1
npm ERR! node_modules/react
npm ERR!   react@"17.0.1" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer react@"^15.1.0 || ^16.0.0" from react-router-sitemap@1.2.0
npm ERR! node_modules/react-router-sitemap
npm ERR!   react-router-sitemap@"1.2.0" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.

It is currently not working with npm 7 and React 17 in default mode.

[Abokorhassan]

Here's what helped me... use it with the legacy flag like this:- npm i react-router-sitemap --legacy-peer-deps

[starhound]

Same for React 18.2, command above works though