This commit implements a new boolean input to the action,
`follow-symlinks`. This option configures whether the glob expansion
will follow any symlinks it finds when determining the set of of files
to be archived into the artifact.
The default value of the option, which preserves the existing behaviour,
is `true`. When set to true, symbolic links will be be followed and expanded
If `false`, symbolic links will be included in the archived artifact verbatim.
Users may wish to set this option to false if their artifact contains
internally-referencing symlinks which would result in significant bloat
(and semantic change!) in the source files when the artifact is created.
Resolves: actions#93.
