chore(react-router): Fix casing on deprecation notices (#18221)

Author: andreiborza

packages/react-router/src/client/index.ts

@@ -6,13 +6,13 @@ export { reactRouterTracingIntegration } from './tracingIntegration';
 export { captureReactException, reactErrorHandler, Profiler, withProfiler, useProfiler } from '@sentry/react';
 
 /**
- * @deprecated ErrorBoundary is deprecated, use react router's error boundary instead.
+ * @deprecated ErrorBoundary is deprecated, use React Router's error boundary instead.
  * See https://docs.sentry.io/platforms/javascript/guides/react-router/#report-errors-from-error-boundaries
  */
 export { ErrorBoundary, withErrorBoundary } from '@sentry/react';
 
 /**
- * @deprecated ErrorBoundaryProps and FallbackRender are deprecated, use react router's error boundary instead.
+ * @deprecated ErrorBoundaryProps and FallbackRender are deprecated, use React Router's error boundary instead.
  * See https://docs.sentry.io/platforms/javascript/guides/react-router/#report-errors-from-error-boundaries
  */
 export type { ErrorBoundaryProps, FallbackRender } from '@sentry/react';