Minor readme improvements

@charlierudolph what do you think about this?
I think the inner bullets can be trimmed down now that you they are under `minimize network requests` 

```
each command performs a single fetch 
```
remote is inherent since we are talking about network requests and the fetch command. only doesn't really add anything to the sentence in my mind 

````
skips unnecessary pushes
```
this is the terminology used in the release notes