Update README and LICENSE files

Add history of RGBDS and original license.

Signed-off-by: AntonioND <antonio_nd@outlook.com>

LICENSE.md

@@ -1,5 +1,32 @@
-rgbasm and rgblink are derived from Justin Lloyd's RGBDS, which is
+# Original code
-released under the following license:
+
+Copyright (C) 1997  Carsten Sorensen <surfsmurf@matilde.demon.co.uk>
+
+The ASMotor package (xAsm, xLink, RGBFix, examples and documentation) is
+freeware and distributed as is. The author retains his copyright and right to
+modify the specifications and operation of the software without notice.
+
+In other words this means I encourage you to...
+
+- use it for whatever purpose even professional work without me charging you a
+  penny
+- copy it to another person (wholly or in part, though I'm sure he'd appreciate
+  the whole package) in whatever form you find suitable
+- mass-distribute the ASMotor package if it is complete (xAsm, xLink, RGBFix and
+  documentation).
+- contact me if you have any problems
+
+This also means you can't...
+
+- blame me for loss of profit, data, sleep, food or other nasty things through
+  the use or distribution of ASMotor. If you choose to use ASMotor  you do so at
+  your own risk.
+- expect me to be able to help you should you have a problem related or not to
+  ASMotor.
+
+# Otaku no Zoku's modifications
+
+Copyright (C) 1999  Justin Lloyd <jlloyd@imf.la> (?)
 
                       DO WHATEVER PUBLIC LICENSE*
    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
@@ -14,6 +41,13 @@ released under the following license:
 
  Software originally created by Justin Lloyd @ http://otakunozoku.com/
 
+# rgbds-linux
+
+Copyright (C) 2009  Vegard Nossum <vegard.nossum@gmail.com>
+
+# Current
+
+rgbasm and rgblink are derived from Justin Lloyd's RGBDS.
 
 rgbfix was rewritten from scratch by Anthony J. Bentley, and is released
 under the ISC license; see the source file for the text of the license.

README.md

@@ -133,3 +133,19 @@ This is the complete list of user-defined variables:
 - `BINMODE`: Permissions of the installed binaries. Defaults to `555`.
 
 - `MANMODE`: Permissions of the installed manpages. Defaults to `444`.
+
+## 3 History
+
+- Around 1997, Carsten Sorensen (AKA SurfSmurf) writes ASMotor as a
+  general-purpose assembler/linker system for DOS/Win32
+
+- Around 1999, Justin Lloyd (AKA Otaku no Zoku) adapts ASMotor to read and
+  produce GBZ80 assembly/machine code, and releases this version as RGBDS.
+
+- 2009, Vegard Nossum adapts the code to be more UNIX-like and releases this
+  version as rgbds-linux on [GitHub](https://github.com/vegard/rgbds-linux).
+
+- 2010, Anthony J. Bentley forks that repository. The fork becomes the reference
+  implementation of rgbds.
+
+- 2017, Bentley's repository is moved to a neutral name.