[VoiceOver] Post Settings concerns

<img src="https://user-images.githubusercontent.com/198826/68971251-588fb500-07a6-11ea-883c-5cfa9943f55c.png" width="320">

Main

• [ ] Set Featured Image is not a button
• [ ] Set Location is not a button
• [ ] If there is a location and a map is shown, the map pin and other elements are accessible. They don't need to be and it's probably not that useful.

Post Categories

• [ ] The Add button's label is confusing: “icon post add”
• [ ] Cells do not have the .button trait

Add A Category

• [ ] Parent Category selection -> Cells do not have the .button trait

Tags

• [ ] The tag cells do not have .button trait
• [ ] When selecting a suggested tag, the focus goes to the text editor but this is not announced

Published On

• [ ] The “Date and Time” cell can be a .button