docs: better docs, mv doxygen to sphinx

This patch refactors the VPP sphinx docs
in order to make it easier to consume
for external readers as well as VPP developers.

It also makes sphinx the single source
of documentation, which simplifies maintenance
and operation.

Most important updates are:

- reformat the existing documentation as rst
- split RELEASE.md and move it into separate rst files
- remove section 'events'
- remove section 'archive'
- remove section 'related projects'
- remove section 'feature by release'
- remove section 'Various links'
- make (Configuration reference, CLI docs,
  developer docs) top level items in the list
- move 'Use Cases' as part of 'About VPP'
- move 'Troubleshooting' as part of 'Getting Started'
- move test framework docs into 'Developer Documentation'
- add a 'Contributing' section for gerrit,
  docs and other contributer related infos
- deprecate doxygen and test-docs targets
- redirect the "make doxygen" target to "make docs"

Type: refactor

Change-Id: I552a5645d5b7964d547f99b1336e2ac24e7c209f
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>
diff --git a/docs/cli-reference/interface/hardware.rst b/docs/cli-reference/interface/hardware.rst
new file mode 100644
index 0000000..0d12438
--- /dev/null
+++ b/docs/cli-reference/interface/hardware.rst
@@ -0,0 +1,161 @@
+.. _interface:
+
+.. toctree::
+
+Hardware-Interfaces Commands
+============================
+This section contains those interface commands that are related to hardware-interfaces:
+
+
+* `Show Bridge-Domain`_
+* `Show Hardware-Interfaces`_
+* `Clear Hardware-Interfaces`_
+
+.. note:: For a complete list of CLI Debug commands refer to the Debug CLI section of the `Source Code Documents <https://docs.fd.io/vpp/18.07/clicmd.html>`_ .
+
+Show Bridge-Domain
++++++++++++++++++++
+
+Show a summary of all the bridge-domain instances or detailed view of a single bridge-domain.
+Bridge-domains are created by adding an interface to a bridge using the **set interface l2 bridge** command.
+
+
+.. code-block:: console
+
+    show bridge-domain [*bridge-domain-id* [detail|int|arp| *bd-tag* ]]
+
+
+Example Usage
+-------------
+.. code-block:: console
+
+    Example of displaying all bridge-domains:
+
+    vpp# show bridge-domain
+
+     ID   Index   Learning   U-Forwrd   UU-Flood   Flooding   ARP-Term     BVI-Intf
+     0      0        off        off        off        off        off        local0
+    200     1        on         on         on         on         off          N/A
+
+    Example of displaying details of a single bridge-domains:
+
+    vpp# show bridge-domain 200 detail
+
+     ID   Index   Learning   U-Forwrd   UU-Flood   Flooding   ARP-Term     BVI-Intf
+    200     1        on         on         on         on         off          N/A
+
+             Interface           Index  SHG  BVI        VLAN-Tag-Rewrite
+     GigabitEthernet0/8/0.200      3     0    -               none
+     GigabitEthernet0/9/0.200      4     0    -               none
+
+Declaration and Implementation
+------------------------------
+
+**Declaration:** bd_show_cli (src/vnet/l2/l2_bd.c line 1151)
+
+**Implementation:** bd_show
+
+Show Hardware-Interfaces
++++++++++++++++++++++++++
+Display more detailed information about all or a list of given
+interfaces. The verboseness of the output can be controlled by the
+following optional parameters:
+
+-  **brief**: Only show name, index and state (default for bonded
+   interfaces).
+-  **verbose**: Also display additional attributes (default for all other
+   interfaces).
+-  **detail**: Also display all remaining attributes and extended
+   statistics.
+
+.. note::
+	To limit the output of the command to bonded interfaces and their
+	slave interfaces, use the '*bond*' optional parameter.
+
+
+.. code-block:: shell
+
+    show hardware-interfaces [brief|verbose|detail] [bond] [<interface> [<interface> [..]]] [<sw_idx> [<sw_idx> [..]]].
+
+
+Examples
+--------
+Example of how to display default data for all interfaces:
+
+.. code-block:: console
+
+    vpp# show hardware-interfaces
+                  Name                Idx   Link  Hardware
+    GigabitEthernet7/0/0               1     up   GigabitEthernet7/0/0
+      Ethernet address ec:f4:bb:c0:bc:fc
+      Intel e1000
+        carrier up full duplex speed 1000 mtu 9216
+        rx queues 1, rx desc 1024, tx queues 3, tx desc 1024
+        cpu socket 0
+    GigabitEthernet7/0/1               2     up   GigabitEthernet7/0/1
+      Ethernet address ec:f4:bb:c0:bc:fd
+      Intel e1000
+        carrier up full duplex speed 1000 mtu 9216
+        rx queues 1, rx desc 1024, tx queues 3, tx desc 1024
+        cpu socket 0
+    VirtualEthernet0/0/0               3     up   VirtualEthernet0/0/0
+      Ethernet address 02:fe:a5:a9:8b:8e
+    VirtualEthernet0/0/1               4     up   VirtualEthernet0/0/1
+      Ethernet address 02:fe:c0:4e:3b:b0
+    VirtualEthernet0/0/2               5     up   VirtualEthernet0/0/2
+      Ethernet address 02:fe:1f:73:92:81
+    VirtualEthernet0/0/3               6     up   VirtualEthernet0/0/3
+      Ethernet address 02:fe:f2:25:c4:68
+    local0                             0    down  local0
+      local
+
+Example of how to display *verbose* data for an interface by name and software index
+(where 2 is the software index):
+
+.. code-block:: console
+
+    vpp# show hardware-interfaces GigabitEthernet7/0/0 2 verbose
+                   Name                Idx   Link  Hardware
+    GigabitEthernet7/0/0               1     up   GigabitEthernet7/0/0
+      Ethernet address ec:f4:bb:c0:bc:fc
+      Intel e1000
+        carrier up full duplex speed 1000 mtu 9216
+        rx queues 1, rx desc 1024, tx queues 3, tx desc 1024
+        cpu socket 0
+    GigabitEthernet7/0/1               2    down  GigabitEthernet7/0/1
+      Ethernet address ec:f4:bb:c0:bc:fd
+      Intel e1000
+        carrier up full duplex speed 1000 mtu 9216
+        rx queues 1, rx desc 1024, tx queues 3, tx desc 1024
+        cpu socket 0
+
+Clear Hardware-Interfaces
++++++++++++++++++++++++++
+
+Clear the extended statistics for all or a list of given interfaces
+(statistics associated with the **show hardware-interfaces** command).
+
+
+.. code-block:: shell
+
+    clear hardware-interfaces [<interface> [<interface> [..]]] [<sw_idx> [<sw_idx> [..]]].
+
+
+Examples
+--------
+
+Example of how to clear the extended statistics for all interfaces:
+
+
+.. code-block:: console
+
+        vpp# clear hardware-interfaces
+
+Example of how to clear the extended statistics for an interface by name and software index
+(where 2 is the software index):
+
+.. code-block:: console
+
+        vpp# clear hardware-interfaces GigabitEthernet7/0/0 2
+
+