m_add_sphere: Add Sphere Shape
In r3dmol: Create Interactive 3D Visualizations of Molecular Data

Adds sphere at given location, with given radius.

1	m_add_sphere(id, center, radius = 1, spec = m_shape_spec(), ...)

`id`	R3dmol `id` or a `r3dmol` object (the output from `r3dmol()`)
`center`	center point of sphere. Can be `m_sel()`.
`radius`	radius of sphere.
`spec`	Additional shape specifications defined with `m_shape_spec()`.
`...`	Additional shape specifcations, that can be called outside of `m_shape_spec()` such as `color = 'blue'`

r3dmol() %>%
  m_add_model(data = m_fetch_pdb("1bna")) %>%
  m_add_sphere(
    center = m_sel(resi = 1),
    spec = m_shape_spec(color = "green", wireframe = TRUE)
  ) %>%
  m_zoom_to(sel = m_sel(resi = 1))