React Tutorial Improvements (#5657)

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## About the changes
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being introduced? Feel free to also add screenshots or steps to view the
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We've made some first round updates to the React tutorial:

- making it more SEO-friendly with ordered lists, sequential language,
description of the JS library
- Switched over the demo app to point to an open source project:
[Cypress Real World
App](https://github.com/cypress-io/cypress-realworld-app)
- included best practice considerations for client-side development
- updated URL path to point to `/feature-flag-tutorials/react` for
simplification


## Discussion points
<!-- Anything about the PR you'd like to discuss before it gets merged?
Got any questions or doubts? -->

Would love feedback on if there's a need for more screenshots? Don't
want to be too screenshot-heavy though I imagine.
And need feedback on the descriptions of "Considerations for using
feature flags in react"
https://github.com/Unleash/unleash/compare/react-improvements?expand=1#diff-96d4956f49f80cd76489a72d4d88c2956ce9dcc695f66fe014ad1185e37cb589R21

Want to make sure that what I described makes sense or if it could use
some tweaking to convey the right message clearly.

website/docusaurus.config.js

@@ -550,7 +550,7 @@ module.exports = {
                     },
                     {
                         from: '/topics/feature-flags/tutorials/react/implementing-feature-flags',
-                        to: '/feature-flag-tutorials/react/implementing-feature-flags',
+                        to: '/feature-flag-tutorials/react',
                     },
                     {
                         from: '/topics/feature-flags/tutorials/flutter/a-b-testing',
@@ -562,8 +562,8 @@ module.exports = {
                     },
                     {
                         from: [
-                             '/tutorials/academy',
-                             '/unleash-academy',
+                            '/tutorials/academy',
+                            '/unleash-academy',
                         ],
                         to: '/unleash-academy/introduction',
                     },
@@ -664,7 +664,7 @@ module.exports = {
                         to: '/using-unleash/deploy/configuring-unleash-v3',
                     },
                     {
-                        from : [
+                        from: [
                             '/reference/deploy/database-setup',
                             '/deploy/database-setup',
                         ],
@@ -692,7 +692,7 @@ module.exports = {
                         to: '/using-unleash/deploy/google-auth-hook',
                     },
                     {
-                        from:[
+                        from: [
                             '/deploy/migration_guide',
                             '/reference/deploy/migration-guide',
                         ],
@@ -794,5 +794,5 @@ module.exports = {
     ],
     clientModules: [
         require.resolve('./global.js'),
-      ],
+    ],
 };