Suggestion commands

Unsupported suggestion commands

To implement support for a command, see here

FT.SUGADD (not implemented)

Adds a suggestion string to an auto-complete suggestion dictionary

FT.SUGGET (not implemented)

Gets completion suggestions for a prefix

FT.SUGDEL (not implemented)

Deletes a string from a suggestion index

FT.SUGLEN (not implemented)

Gets the size of an auto-complete suggestion dictionary