mention another Go client

implement showDatabaseProperty()

import tests from go-notion

fix newRequestJSON() to always set body even if params is nil; add Time.Equal()

link to other API clients

add links to examples from readme.md

add example for CreatePage()

fix JSON decoding of struct Date; remove unused util.go

fixes to decoding DatabasePageProperty

change encoding from CRLF => LF

add example for Search()

shorten Search(); add link to unofficial API client

add chages from https://github.com/dstotijn/go-notion/commit/55aa9db5c7a72af2a57ac953ebbbdbdec3e1efa1

import changes from https://github.com/dstotijn/go-notion/commit/ce7d6da4c678d14dfa1fd8c2a013a389ecbd23ff

add example for QueryDatabas(); import changes from https://github.com/dstotijn/go-notion/commit/c16fdfbc88c2ca8734bd23880361107c36188bed and https://github.com/dstotijn/go-notion/commit/0e0f6c77aa76c27956632a4315b9cba5ec3535dc