Add Tag to Post

[askingalot]

As a post connoisseur I would like to tag a post with a keyword to make searching easier.

Given the user is viewing the Post Details menu
When they select the option to add a tag
Then they should be presented with a list of available tags to choose from

Given the user chooses a tag
When they enter the selection and hit enter
Then the relationship between the tag and the post should be saved to the database