[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/overview/contributing/copyright/Makefile.rst b/overview/contributing/copyright/Makefile.rst
index cb93667..9f9c5b1 100644
--- a/overview/contributing/copyright/Makefile.rst
+++ b/overview/contributing/copyright/Makefile.rst
@@ -5,7 +5,7 @@
    :caption: Makefile Syntax
 
 # -----------------------------------------------------------------------
-# Copyright 2017-2024 Open Networking Foundation Contributors
+# Copyright 2017-2026 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.
@@ -19,7 +19,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # -----------------------------------------------------------------------
-# SPDX-FileCopyrightText: 2017-2024 Open Networking Foundation Contributors
+# SPDX-FileCopyrightText: 2017-2026 Linux Foundation Broadband Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
 # Intent:
diff --git a/overview/contributing/copyright/copyright.rst b/overview/contributing/copyright/copyright.rst
index 19737f6..233ff4f 100644
--- a/overview/contributing/copyright/copyright.rst
+++ b/overview/contributing/copyright/copyright.rst
@@ -1,9 +1,9 @@
 Copyright Notice
 ================
 
-Include a copyright notice with all submissions to ONF repositoreis.
+Include a copyright notice with all submissions to LF BB repositoreis.
 
-- ``Copyright 2017-2023 Open Networking Foundation Contributors``
+- ``Copyright 2017-2023 LF BB Contributors``
 - NOTE: Range values such as -present are not legally binding
 
   - Copyright notice should be dated to the last year sources were modified.
diff --git a/overview/contributing/copyright/golang.rst b/overview/contributing/copyright/golang.rst
index 13ec153..2c0e045 100644
--- a/overview/contributing/copyright/golang.rst
+++ b/overview/contributing/copyright/golang.rst
@@ -5,7 +5,7 @@
    :caption: Copyright Syntax
 
    /* -----------------------------------------------------------------------
-    * Copyright 2017-2024 Open Networking Foundation Contributors
+    * Copyright 2017-2026 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.
@@ -19,7 +19,7 @@
     * See the License for the specific language governing permissions and
     * limitations under the License.
     * -----------------------------------------------------------------------
-    * SPDX-FileCopyrightText: 2017-2024 Open Networking Foundation Contributors
+    * SPDX-FileCopyrightText: 2017-2026 Linux Foundation Broadband Contributors
     * SPDX-License-Identifier: Apache-2.0
     * -----------------------------------------------------------------------
     */
diff --git a/overview/contributing/copyright/json.rst b/overview/contributing/copyright/json.rst
index 18b0776..75676f5 100644
--- a/overview/contributing/copyright/json.rst
+++ b/overview/contributing/copyright/json.rst
@@ -10,7 +10,7 @@
           "version": 1,
       },
       "copyright-notice" : {
-          "SPDX-FileCopyrightText" : "2024 Open Networking Foundation Contributors",
+          "SPDX-FileCopyrightText" : "2026 Linux Foundation Broadband Contributors",
           "SPDX-License-Identifier" : "Apache-2.0"
       }
    }
diff --git a/overview/contributing/copyright/markdown.rst b/overview/contributing/copyright/markdown.rst
index e57068e..8082acd 100644
--- a/overview/contributing/copyright/markdown.rst
+++ b/overview/contributing/copyright/markdown.rst
@@ -6,7 +6,8 @@
 
    <!--
    # -----------------------------------------------------------------------
-   # Copyright 2017-2024 Open Networking Foundation Contributors
+   # Copyright 2017-2026 Linux Foundation Broadband Contributors
+   # Copyright 2017-2024 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.
@@ -20,7 +21,7 @@
    # See the License for the specific language governing permissions and
    # limitations under the License.
    # -----------------------------------------------------------------------
-   # SPDX-FileCopyrightText: 2017-2024 Open Networking Foundation Contributors
+   # SPDX-FileCopyrightText: 2017-2026 Linux Foundation Broadband Contributors
    # SPDX-License-Identifier: Apache-2.0
    # -----------------------------------------------------------------------
    # Intent: