Base Structure doesn't include inputs??

[vortexing]

https://github.com/openwdl/wdl-docs/blob/main/docs/WDL/Base_structure.md

In this md, I find it strange that the 'input' section of a task or the workflow was not included. Also I feel like perhaps the base structure of the workflow should not be mixed when explaining it with the components of a task.

So workflow:

• input
• call/task
• output

And Task:

• input
• command
• output

I can attempt to edit and PR if folks aren't opposed to this.

[ekiernan]

@vortexing Not opposed at all! And happy to review anything you want. Thank you for helping to make this better!