add outlineWeight & outlineColor to columnHeaders

[DavidS-BDO]

Adding additional controls to the columnHeaders

[github-actions[bot]]

Hi @DavidS-BDO! Thank you for opening your first Pull Request. Please add any information we might need in the comments, make sure any issues you are resolving are linked ( what is this? ), and one of our project maintainers will review it soon. Thank you for making Power BI Theme Templates better!