* Minor heading update according to the guideline
Fixed title of the document to use title case as described in the community guidelines.
* Capitalization fixes.
`https://openservicebrokerapi.org/` contains information such as `what are service brokers?`, how they work, building services for Kubernetes using `Open Service Broker API` etc.
* Rename architecture section
"Kubernetes" goes without saying. This section is mainly talking about
cluster architecture, so make the title match that.
* Introduce “cluster” before Cluster Architecture section
Make sure the reader can learn what a cluster is before they read about
elements of cluster architecture.
I changed a question that had no question mark into a statement. I also changed the heading from the first person to the second person, because the topic it treats the reader as the second person everywhere else.
* Updates the What is Kubernetes page
* Adds content to the what is kubernetes used for section.
* Updates the ordered list.
* Formats the content.
* Update the content as per the comments
* Fix a broken link