docs(solid): adds TanStack Router Solid docs page (#15054)

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## DESCRIBE YOUR PR

This PR is the documentation complement to
getsentry/sentry-javascript#17735 which adds
support for TanStack Router Solid within Sentry.

## IS YOUR CHANGE URGENT?  

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- [x] Low: I can wait a week but I would love for this to be merged and
the `@sentry/solid` package to be updated + published as soon as
possible as I am building an enterprise application using Sentry +
TanStack Router Solid

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## EXTRA RESOURCES

- [Sentry Docs contributor guide](https://docs.sentry.io/contributing/)

---------

Co-authored-by: Andrei <168741329+andreiborza@users.noreply.github.com>

Author: thedanchez

docs/platforms/javascript/guides/solid/features/tanstack-router.mdx

@@ -0,0 +1,49 @@
+---
+title: TanStack Router
+description: "Learn about Sentry's TanStack Router integration."
+---
+
+The TanStack Router integration is included in the `@sentry/solid` package and is compatible with version `1.132.27` of `@tanstack/solid-router` and above.
+
+<Alert title="Note">
+
+The TanStack Router integration is designed to work with Sentry Tracing. Please see <PlatformLink to="/tracing/#enable-tracing">Getting Started with Solid Performance</PlatformLink> for more details on how to set up and install the SDK.
+
+</Alert>
+
+The TanStack Router instrumentation uses your TanStack Router routes to create `pageload` and `navigation` transactions to ensure you collect meaningful performance data about the health of your page loads and associated requests.
+
+## Usage
+
+To use the TanStack Router integration, pass the `Sentry.tanstackRouterBrowserTracingIntegration` inside your `integrations` option:
+
+```javascript
+import * as Sentry from "@sentry/solid";
+import { tanstackRouterBrowserTracingIntegration } from '@sentry/solid/tanstackrouter';
+import { createRouter } from "@tanstack/solid-router";
+
+const router = createRouter({
+  // Your router options...
+});
+
+declare module '@tanstack/solid-router' {
+  interface Register {
+    router: typeof router;
+  }
+}
+
+Sentry.init({
+  dsn: "___PUBLIC_DSN___",
+  integrations: [tanstackRouterBrowserTracingIntegration(router)],
+
+  // Setting a sample rate is required for sending performance data.
+  // We recommend adjusting this value in production, or using tracesSampler
+  // for finer control.
+  tracesSampleRate: 1.0,
+});
+```
+
+## Next Steps:
+
+- [Return to **Getting Started**](../../)
+- [Return to the main integrations page](../)