Release 0.171.1

Defect fixes:

• Fixed issue #441 concerning misaligned allocation for string data.

• Fixed issue #436 concerning overflow warning.

• Changed internal variable names to avoid shadow warnings

• Fixed signature of dump_pretty #438

• Fixed basic_json_decode_options constructor #437

Enhancements:

• Improved error messages (with field names) for invalid type mappings when using the
  json_type_traits convenience macros.

• Support char8_t and u8string for C++ 20

• Added compare for bigint/bigdec/bigfloat as double or exact text match. This makes
  JSON Query work if you use options.lossless_number(true) for parsing JSON.