docs(js): React Quick Start guide for Tracing

[inventarSarah]

DESCRIBE YOUR PR

Rework the React Getting Started page into a Quick Start guide.

This branch focuses on content relevant for Tracing and concludes the transformation of the React Getting Started guide into a Quick Start guide.

Closes: #12991

IS YOUR CHANGE URGENT?

Help us prioritize incoming PRs by letting us know when the change needs to go live.

• Urgent deadline (GA date, etc.):
• Other deadline:
• None: Not urgent, can wait up to 1 week+

SLA

• Teamwork makes the dream work, so please add a reviewer to your PRs.
• Please give the docs team up to 1 week to review your PR unless you've added an urgent due date to it.
  Thanks in advance for your help!

PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

EXTRA RESOURCES

• Sentry Docs contributor guide

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
sentry-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 3, 2025 1:44pm

2 Skipped Deployments

Name	Status	Preview	Comments	Updated (UTC)
changelog	⬜️ Ignored (Inspect)	Visit Preview		Apr 3, 2025 1:44pm
develop-docs	⬜️ Ignored (Inspect)	Visit Preview		Apr 3, 2025 1:44pm

[codecov]

Bundle Report

Changes will decrease total bundle size by 15 bytes (-0.0%) ⬇️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
sentry-docs-server-cjs	10.63MB	-9 bytes (-0.0%) ⬇️
sentry-docs-client-array-push	9.45MB	-6 bytes (-0.0%) ⬇️

Affected Assets, Files, and Routes:

view changes for bundle: sentry-docs-client-array-push

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
static/chunks/pages/_app-*.js	-3 bytes	868.67kB	-0.0%
static/chunks/8931-*.js	-3 bytes	397.42kB	-0.0%
static/i7Lex5J1n-*.js (New)	77 bytes	77 bytes	100.0% 🚀
static/i7Lex5J1n-*.js (New)	578 bytes	578 bytes	100.0% 🚀
static/vKgJs-*.js (Deleted)	-77 bytes	0 bytes	-100.0% 🗑️
static/vKgJs-*.js (Deleted)	-578 bytes	0 bytes	-100.0% 🗑️

view changes for bundle: sentry-docs-server-cjs

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
1729.js	-3 bytes	1.58MB	-0.0%
../instrumentation.js	-3 bytes	911.63kB	-0.0%
9523.js	-3 bytes	887.68kB	-0.0%

[mydea]

nice!