get_block_polygons: Create polygons of a block with plots
In smmueller/plotdesignr: Design Agronomic Field Experiments with more Power

Create polygons of a block with plots

get_block_polygons(
  treatment_number,
  plot_length,
  plot_width,
  border_width,
  crs,
  origin
)

`treatment_number`	integer; the number of treatments or plots that should be included in each block.
`plot_length`	numeric; desired plot length in meters.
`plot_width`	numeric; desired plot width in meters.
`border_width`	numeric; desired width between plots in meters.
`crs`	crs; coordinate referense system to be applied to new polygons.
`origin`	numeric vector; optional a named vector of the xy point of the bottom left (south west) corner of the block. Must have the names `x` and `y`. This should be provided if creating a connected (traditional) experiment.
`centroid`	numeric vector; optional a named vector of the xy point of the desired block centroid. Must have the names `x` and `y`. This should be provided if creating a disconnected experiment.