Add instructions to create oem.target file

 - Add missing oem.target file mentioned in OEM .service files
 - Also small spelling / grammar fixes

Fixes #110. Alternatively, oem.target could be built into the CoreOS image instead.
feat(ec2): update userdata instructions
Merge pull request #112 from robszumski/master

feat(ec2): update userdata instructions
Merge pull request #111 from mikemaccana/patch-4

Add instructions to create oem.target file
fix(getting-started-etcd): add recursive flag to watch command
Merge pull request #113 from robszumski/master

fix(getting-started-etcd): add recursive flag to watch command
no wget on OS X

use curl instead
unzip to a named directory

otherwise it just unzips in the current directory and the next step is wrong
Merge pull request #114 from willie/patch-1

no wget on OS X
fix clone URL

Using previous docs:

```
$ git clone https://github.com/coreos/coreos-vagrant/
Cloning into 'coreos-vagrant'...
ERROR: Repository not found.
fatal: Could not read from remote repository.
```
Merge pull request #116 from nnutter/master

feat(vagrant): fix clone URL
Merge pull request #115 from robszumski/master

feat(fleet): launching containers with fleet guide
feat(getting-started-docker): rewrite commiting a container instructions