Allow zebra search for Lexile numbers in field 521$a

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>

etc/zebradb/biblios/etc/bib1.att

@@ -106,6 +106,7 @@ att 1035    Anywhere
 att 1036    Author-Title-Subject
 att 1079    Subject-topical
 
+
 # Koha Local-Use Biblio Indexes
 att 9001    Control-number
 att 9002    biblioitemnumber
@@ -183,3 +184,5 @@ att 8703    ff7-01-02
 att 9900    Author-personal-bibliography
 # Author-in-order - firstname lastname in 245$c statement of responsibility
 att 9902    Author-in-order
+# Lexile number
+att 9903    lex

etc/zebradb/ccl.properties

@@ -1031,6 +1031,9 @@ l-format 1=8703
 
 Illustration-code 1=Illustration-code 
 
+# Lexile Number
+lex 1=9903 r=r
+
 ## Statuses
 popularity 1=issues
 

etc/zebradb/marc_defs/marc21/biblios/record.abs

@@ -147,6 +147,7 @@ melm 505$t      Title
 melm 505        Note:w,Note:p
 melm 510        Indexed-by
 melm 520        Abstract:w,Abstract:p
+melm 521$a      lex:n
 #melm 533$d     pubdate,pubdate:s
 #melm 541$d     Date-of-acquisition,Date-of-acquisition:s
 melm 590        Note:w,Note:p