Fixup typos in README.md (#134)

Author: xginn8

packages/opencensus-nodejs/README.md

@@ -33,9 +33,9 @@ import * as tracing from '@opencensus/nodejs';
 tracing.start();
 ```
 
-### Manualy Instrument an Application
+### Manually Instrument an Application
 
-In addition to automatic tracing, it is possible to manualy create your own root and child spans. 
+In addition to automatic tracing, it is possible to manually create your own root and child spans. 
 
 ```typescript
 const rootSpanOptions = { name: 'your root span' };