openxlsx update

[ycphs]

Please specify whether your issue is about:

• [x] a suggested code or documentation change, improvement to the code, or feature request

In the documentation there is an error.

export(list(mtcars1 = mtcars[1:10,], 
            mtcars2 = mtcars[11:20,],
             mtcars2 = mtcars[21:32,]), "mtcars.xlsx")

the following correction solves the issue

export(list(mtcars1 = mtcars[1:10,], 
            mtcars2 = mtcars[11:20,],
             mtcars3 = mtcars[21:32,]), "mtcars.xlsx")

[ycphs]

I provided a PR.

Please check #284