change_stereotype: change_stereotype Function
In langdoc/FRelan: Parse and analyze ELAN files

This function adds a new tier into an ELAN file. It is prototypical at best.

1 2	change_stereotype(file, linguistic_type, stereotype, time_alignable, add = FALSE)

`file`	ELAN file
`linguistic_type`	Name of the linguistic type
`stereotype`	Name of the stereotype. Accepted values are, among some others, "Included_in", "Symbolic_Association" or "Symbolic_Subdivision".
`time_alignable`	Here the accepted values are "true" or "false". Please note that these must be character vectors typed exactly like this.
`add`	Should the type be added, or is it intended to modify an existing type with the same name?