Mapping wp values to colours to enable legend & custom ordering of bars

[erstearns]

For starters, what an awesome package! Also, this PR corresponds to issue #54 -- ended up figuring it out!

I am using this a bit differently than it was designed for -- instead of project planning, I am using it to depict project work done. I am part of a dynamic team that provides technical support to different groups and the team leader is looking for a gantt chart depicting all the different project supported since 2020 through to present.

I have edited the ganttrify function to:

• Use an arg, order_by, to inform the ordering (top to bottom) of bars/projects
• Following on to that, a new arg order_ascending, to indicate type of ordering
• Use an arg, colour_by, that allows specification of which column to use for colouring the project bars
• Ensure the values of the colour_by field are mapped to actual colors to enable inclusion of a useful legend
• Use an arg, include_legend, to keep legend for colour_by field; also added necessary adjustments to make sure mapping was done properly
• Following on to include_legend, also added an arg, legend_title to allow the user to specify a legend title.
• Added necessary strsplit() header information corresponding to each new arg

New args:

• colour_by
• order_by
• order_ascending
• include_legend
• legend_title

Woohoo!

[giocomai]

Thanks a lot for taking the time! I'm travelling these days, but in the coming weeks I should be able to take a look!