feat(seer): document the seer github app

[jennmueng]

DESCRIBE YOUR PR

Documents the Seer GitHub App as one of our GitHub integrations + links to this new docs section from various places its mentioned.

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+

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

[vercel]

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Project	Deployment	Preview	Comments	Updated (UTC)
sentry-docs	Ready	Preview	Comment	Oct 16, 2025 8:55pm

1 Skipped Deployment

Project	Deployment	Preview	Comments	Updated (UTC)
develop-docs	Ignored	Preview		Oct 16, 2025 8:55pm

[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-client-array-push	10.16MB	-6 bytes (-0.0%) ⬇️
sentry-docs-server-cjs	12.98MB	-9 bytes (-0.0%) ⬇️

Affected Assets, Files, and Routes:

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

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
1729.js	-3 bytes	1.78MB	-0.0%
../instrumentation.js	-3 bytes	1.1MB	-0.0%
9523.js	-3 bytes	1.08MB	-0.0%

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	882.71kB	-0.0%
static/chunks/8321-*.js	-3 bytes	425.87kB	-0.0%
static/AS-*.js (New)	77 bytes	77 bytes	100.0% 🚀
static/AS-*.js (New)	684 bytes	684 bytes	100.0% 🚀
static/RFCUBPwtyb0L1nnCUC4Jm/_buildManifest.js (Deleted)	-684 bytes	0 bytes	-100.0% 🗑️
static/RFCUBPwtyb0L1nnCUC4Jm/_ssgManifest.js (Deleted)	-77 bytes	0 bytes	-100.0% 🗑️