Update COPYING-DOCS from GNU website (#152)

https://www.gnu.org/licenses/fdl-1.3.txt

COPYING-DOCS

@@ -4,7 +4,7 @@
 
 
  Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
-     <http://fsf.org/>
+     <https://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
@@ -377,7 +377,7 @@ The Free Software Foundation may publish new, revised versions of the
 GNU Free Documentation License from time to time.  Such new versions
 will be similar in spirit to the present version, but may differ in
 detail to address new problems or concerns.  See
-http://www.gnu.org/copyleft/.
+https://www.gnu.org/licenses/.
 
 Each version of the License is given a distinguishing version number.
 If the Document specifies that a particular numbered version of this
@@ -401,19 +401,19 @@ public wiki that anybody can edit is an example of such a server.  A
 "Massive Multiauthor Collaboration" (or "MMC") contained in the site
 means any set of copyrightable works thus published on the MMC site.
 
-"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 
-license published by Creative Commons Corporation, a not-for-profit 
-corporation with a principal place of business in San Francisco, 
-California, as well as future copyleft versions of that license 
+"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
+license published by Creative Commons Corporation, a not-for-profit
+corporation with a principal place of business in San Francisco,
+California, as well as future copyleft versions of that license
 published by that same organization.
 
-"Incorporate" means to publish or republish a Document, in whole or in 
+"Incorporate" means to publish or republish a Document, in whole or in
 part, as part of another Document.
 
-An MMC is "eligible for relicensing" if it is licensed under this 
-License, and if all works that were first published under this License 
-somewhere other than this MMC, and subsequently incorporated in whole or 
-in part into the MMC, (1) had no cover texts or invariant sections, and 
+An MMC is "eligible for relicensing" if it is licensed under this
+License, and if all works that were first published under this License
+somewhere other than this MMC, and subsequently incorporated in whole or
+in part into the MMC, (1) had no cover texts or invariant sections, and
 (2) were thus incorporated prior to November 1, 2008.
 
 The operator of an MMC Site may republish an MMC contained in the site