Support for FT.CREATE PREFIX Parameter

[regisoliveira]

  FT.CREATE {index}
    [ON {structure}]
       [PREFIX {count} {prefix} [{prefix} ..]
       [FILTER {filter}]
       [LANGUAGE {default_lang}]
       [LANGUAGE_FIELD {lang_field}]
       [SCORE {default_score}]
       [SCORE_FIELD {score_field}]
       [PAYLOAD_FIELD {payload_field}]
    [MAXTEXTFIELDS] [TEMPORARY {seconds}] [NOOFFSETS] [NOHL] [NOFIELDS] [NOFREQS] [SKIPINITIALSCAN]
    [STOPWORDS {num} {stopword} ...]
    SCHEMA {field} [TEXT [NOSTEM] [WEIGHT {weight}] [PHONETIC {matcher}] | NUMERIC | GEO | TAG [SEPARATOR {sep}] ] [SORTABLE][NOINDEX] ...

PREFIX {count} {prefix} tells the index which keys it should index. You can add several prefixes to index. Since the argument is optional, the default is * (all keys)

[dengliming]

closed by #17