Fix spelling errors in telemetry README.

pkg/telemetry/README.md

 # telemetry
 
 A library to facilitate reporting analytics and crash reports.
 
 ## Analytics
 
 This library is designed to allow all Dart SDK tools to easily send analytics
 information and crash reports. The tools share a common setting to configure
 sending analytics data. To use this library for a specific tool:
 
 ```
-import 'package:telemtry/telemtry.dart';
+import 'package:telemetry/telemetry.dart';
 import 'package:usage/usage.dart';
 
 main() async {
   final String myAppTrackingID = ...;
   final String myAppName = ...;
 
   Analytics analytics = createAnalyticsInstance(myAppTrackingID, myAppName);
   ...
   analytics.sendScreenView('home');
   ...
   await analytics.waitForLastPing();
 }
 ```
 
 The analytics object reads from the correct user configuration file
 automatically without any additional configuration. Analytics will not be sent
 if the user has opted-out.
 
 ## Crash reporting
 
 To use the crash reporting functionality, import `crash_reporting.dart`, and
 create a new `CrashReportSender` instance:
 
 ```dart
-import 'package:telemtry/crash_reporting.dart';
+import 'package:telemetry/crash_reporting.dart';
 
 main() {
   Analytics analytics = ...;
   CrashReportSender sender = new CrashReportSender(analytics);
   try {
     ...
   } catch (e, st) {
     sender.sendReport(e, st);
   }
 }
 ```
 
 Crash reports will only be sent if the cooresponding [Analytics] object is
 configured to send analytics.