add link to full solr syntax spec
add link to full solr syntax spec

berkmancenter/mediacloud,AchyuthIIIT/mediacloud,AchyuthIIIT/mediacloud,AchyuthIIIT/mediacloud,berkmancenter/mediacloud,AchyuthIIIT/mediacloud,berkmancenter/mediacloud,berkmancenter/mediacloud,AchyuthIIIT/mediacloud,berkmancenter/mediacloud,AchyuthIIIT/mediacloud,AchyuthIIIT/mediacloud,AchyuthIIIT/mediacloud,AchyuthIIIT/mediacloud