refactor: parse query str to should boolean query (#9)

Previously, a query string was converted to a Match query, due to limitaion of
tokenization, the search results may confuse our users[1].  This commit updates
the parsing logic to **expand** query string to a should boolean query, which
should hit more search results and thus is more intuitive for average users, based
on this discussion[2].

[1]: pizza-rs/searchbox#9
[2]: pizza-rs/searchbox#9 (comment)

refactor: parse query str to should boolean query (#9)

Previously, a query string was converted to a Match query, due to limitaion of
tokenization, the search results may confuse our users[1].  This commit updates
the parsing logic to **expand** query string to a should boolean query, which
should hit more search results and thus is more intuitive for average users, based
on this discussion[2].

[1]: pizza-rs/searchbox#9
[2]: pizza-rs/searchbox#9 (comment)

refactor: parse query str to should boolean query (#9)

Previously, a query string was converted to a Match query, due to limitaion of
tokenization, the search results may confuse our users[1].  This commit updates
the parsing logic to **expand** query string to a should boolean query, which
should hit more search results and thus is more intuitive for average users, based
on this discussion[2].

[1]: pizza-rs/searchbox#9
[2]: pizza-rs/searchbox#9 (comment)