Add summary plot as output to domain_mapping function

[RayStick]

Closes #92

Proposed Changes

• domain_mapping.R now outputs a simple high level plot alongside the log file, displaying a count for each domain category
• DESCRIPTION and NAMESPACE are updated to reflect new package dependencies

Checklist before review:

• [x] Please comment on my PR while it's a draft and give me feedback on the development!
• [x] I added everything I wanted to add to this PR, please review!
• [x] The title of this PR is clear and self-explantory.
• [x] I added any appropriate labels to this PR.

[BatoolMM]

It looks good to me @RayStick - all changes are reflected in DESCRIPTION and NAMESPACE.

[RayStick]

Thank you @BatoolMM It would be good to update README actually so I just did that here - add mention of new plot

[RayStick]

Still okay to merge from your perspective?

[BatoolMM]

I forgot the README - I love the graph. Feel free to merge!