fundiversity v0.2.0

Major changes

There is a new function fd_fric_intersect() to compute the intersection of
convex hulls across pairs of sites.
There is a new function fd_fdis to compute Functional Dispersion FDis.
fd_fdiv(), fd_feve(), fd_fdis(), fd_fric() can now be computed in
parallel with the future framework.
Please refer to the parallelization vignette for more information.
The convex hull computation in fd_fdiv(), fd_fric(), and
fd_fric_intersect() is now cached thanks to the
memoise package to speed up repeated runs. This
behaviour can be disabled by running options(fundiversity.memoise = FALSE) at
the start of your R session.