Options for functions in the ggedit package. When running R code, the object ggedit_opts
(default options) is not modified by chunk headers (local chunk options are
merged with default options), whereas ggedit_opts_current (current options)
changes with different chunk headers and it always reflects the options for
the current chunk.
Normally we set up the global options once in the first code chunk in a
document using ggedit_opts$set(), so that all latter chunks will
use these options. Note the global options set in one chunk will not affect
the options in this chunk itself, and that is why we often need to set global
options in a separate chunk.