Brag about RFC 4180 compliance in README (once implemented)

[DivineDominion]

https://www.rfc-editor.org/rfc/rfc4180.html

Things to check and if needed add new tests for:

• Fixing quotes in cells Fix serialization of embedded quotes. #111 (See RFC item 2.7)
• Use CRLF as line/row separators (see RFC item 2.1)
• enquoted CRLF line breaks in cells (see RFC item 2.6)