docs(go): Add server request context docs

[dustinbyrne]

Changes

• Document posthog-go server request context middleware and context-aware helpers for net/http apps.
• Explain tracing headers, request metadata, personless fallback behavior, EvaluateFlagsWithContext, and disabling tracing header capture.
• Link the Go error tracking installation guide to the new request context docs.

Validation: git diff --check

Checklist

• I've read the docs and/or content style guides.
• Words are spelled using American English
• Use relative URLs for internal links
• I've checked the pages added or changed in the Vercel preview build
• If I moved a page, I added a redirect in vercel.json

[github-actions]

Deploy preview

Status	Details	Updated (UTC)
🟢 Ready	View preview	May 28, 2026 02:02PM

[github-actions]

Vale prose linter → found 0 errors, 20 warnings, 0 suggestions in your markdown

Full report → Copy the linter results into an LLM to batch-fix issues.

Linter being weird? Update the rules!

contents/docs/error-tracking/installation/go.mdx — 0 errors, 3 warnings, 0 suggestions

Line	Severity	Message	Rule
2:11	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
22:174	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
107:25	warning	Capitalize 'Logs' for PostHog's product. Use 'logs' for the general industry concept.	PostHogBase.ProductNames

contents/docs/libraries/go/index.mdx — 0 errors, 17 warnings, 0 suggestions

Line	Severity	Message	Rule
6:18	warning	Use 'GitHub' instead of 'github'.	Vale.Terms
6:37	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
88:216	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
88:232	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
117:54	warning	Use the Oxford comma before 'and' or 'or' in a list of three or more items.	PostHogBase.OxfordComma
117:107	warning	'personless' is a possible misspelling.	PostHogBase.Spelling
117:441	warning	'personless' is a possible misspelling.	PostHogBase.Spelling
136:4	warning	'Feature flags' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
136:4	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'Feature flags' for the general industry concept.	PostHogBase.ProductNames
156:8	warning	Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept.	PostHogBase.ProductNames
156:55	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
156:128	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
173:28	warning	Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept.	PostHogBase.ProductNames
173:54	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
175:4	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'Error tracking' for the general industry concept.	PostHogBase.ProductNames
175:4	warning	'Error tracking' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
207:39	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames

[dustinbyrne]

https://bbf87fb1.posthog-preview.pages.dev/docs/libraries/go#request-context