Feature: Add content to a run

In order to populate a run with varied content

As a developer using python-docx

I need a way to add each of the run content elements to a run

Scenario: Add a tab

Given a run

When I add a tab

Then the tab appears at the end of the run

Scenario: Assign mixed text to text property

Given a run

When I assign mixed text to the text property

Then the text of the run represents the textual run content