doc: net_buf: move the network buffer documentation to services

Move the network buffer documentation from networking to services as the
implementation now lives outside of the networking subsystem.

Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>

MAINTAINERS.yml

@@ -2844,6 +2844,7 @@ Networking:
     - tbursztyka
     - jukkar
   files:
+    - doc/services/net_buf/
     - include/zephyr/net/buf.h
     - include/zephyr/net_buf.h
     - lib/net_buf/

doc/connectivity/networking/api/buf_mgmt.rst

@@ -1,10 +1,9 @@
 .. _net_buf_mgmt:
 
-Network Buffer Management
+Network Packet Management
 #########################
 
 .. toctree::
    :maxdepth: 1
 
-   net_buf.rst
    net_pkt.rst

doc/services/index.rst

@@ -22,6 +22,7 @@ OS Services
    tracing/index.rst
    resource_management/index.rst
    mem_mgmt/index.rst
+   net_buf/index.rst
    modbus/index.rst
    modem/index.rst
    notify.rst

doc/services/net_buf/index.rst

@@ -1,7 +1,7 @@
 .. _net_buf_interface:
 
-Network Buffer
-##############
+Network Buffers
+###############
 
 .. contents::
     :local: