[VOL-5545] Update voltha docs

- release notes for VOLTHA versions 2.6 to 2.15 with new Jira links and adjust release schedule details
- update old links
- remove ONF references and links
- update e-mail links
- update copright notices

Change-Id: Id6be18986a8f52f2dfcc07e2b0d2efcb0ae1c0e4
Signed-off-by: serkant.uluderya <serkant.uluderya@netsia.com>
diff --git a/makefiles/config.mk b/makefiles/config.mk
index e3fd8f6..a575d02 100644
--- a/makefiles/config.mk
+++ b/makefiles/config.mk
@@ -6,7 +6,7 @@
 ## -----------------------------------------------------------------------
 
 # -----------------------------------------------------------------------
-# Copyright 2023-2024 Open Networking Foundation Contributors
+# Copyright 2023-2024 Linux Foundation Broadband Contributors
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -22,7 +22,7 @@
 # -----------------------------------------------------------------------
 # https://gerrit.lfbroadband.org/plugins/gitiles/onf-make
 # ONF.makefiles.include.version = 1.1
-# ONF.confg.mk                  = 1.5
+# LF BB.confg.mk                  = 1.5
 # -----------------------------------------------------------------------
 
 --repo-name-- := voltha-docs