[Tracking] Release roadmap

[dr-orlovsky]

Release name	Tracking issue	Est date	Actual date	Release URL
RGB Core concept	n/a	1st Jan 2020	25th Jan 2020	LNP/BP Core Lib 0.1 Alpha 1 & LBX tool
RGB Core preview	n/a	–	24th Jun 2020	RGB Node 0.1 Beta 1
RGB Core testnet1	n/a	1st May 2020	5th Jul 2020	RGB Node 0.1 Beta 2
RGB Core testnet2	n/a	–	12th Aug 2020	RGB Node 0.1 Beta 3
RGB Core testnet3	n/a	–	18th Sept 2020	RGB Node 0.1 Beta 4
RGB Core release	#26	15th Oct 2020	21st Oct 2020	RGB Node 0.1, LNP/BP Core Library
LN basics	n/a	–	26st Oct 2020	LNP Node Alpha
RGB LN preview	#27	1st Nov 2020	5th Nov 2020	LNP Node Beta
RGBv1	#28	1st Feb 20201	n/a	n/a

NB: see PR for all details and subtasks