v0.2.0

• implement binding variable syntax (... as $var)
• implement try catch syntax
• implement alternative operator (//)
• implement various functions (in, to_entries, startswith, endswith, ltrimstr, rtrimstr, combinations, ascii_downcase, ascii_upcase, tojson, fromjson)
• support query for object indexing
• support object construction with variables
• support indexing against strings