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/gettingstarted/progressivevpp/switching.rst b/docs/gettingstarted/progressivevpp/switching.rst
index a28e860..7ee5598 100644
--- a/docs/gettingstarted/progressivevpp/switching.rst
+++ b/docs/gettingstarted/progressivevpp/switching.rst
@@ -80,8 +80,8 @@
 .. code-block:: console
 
    vpp# show bridge-domain
-    ID   Index   Learning   U-Forwrd   UU-Flood   Flooding   ARP-Term     BVI-Intf   
-    0      0        off        off        off        off        off        local0    
+    ID   Index   Learning   U-Forwrd   UU-Flood   Flooding   ARP-Term     BVI-Intf
+    0      0        off        off        off        off        off        local0
 
 In the example above, there is bridge domain ID '0' already. Even though
 sometimes we might get feedback as below:
@@ -175,15 +175,15 @@
 .. code-block:: console
 
     vpp# show l2fib verbose
-    Mac Address     BD Idx           Interface           Index  static  filter  bvi   Mac Age (min) 
-    de:ad:00:00:00:00    1            host-vpp1vpp2           2       0       0     0      disabled    
-    c2:f6:88:31:7b:8e    1            host-vpp1out            1       0       0     0      disabled    
+    Mac Address     BD Idx           Interface           Index  static  filter  bvi   Mac Age (min)
+    de:ad:00:00:00:00    1            host-vpp1vpp2           2       0       0     0      disabled
+    c2:f6:88:31:7b:8e    1            host-vpp1out            1       0       0     0      disabled
     2 l2fib entries
 
 .. code-block:: console
 
     vpp# show l2fib verbose
-    Mac Address     BD Idx           Interface           Index  static  filter  bvi   Mac Age (min) 
-    de:ad:00:00:00:00    1                loop0               2       1       0     1      disabled    
-    c2:f6:88:31:7b:8e    1            host-vpp2vpp1           1       0       0     0      disabled    
+    Mac Address     BD Idx           Interface           Index  static  filter  bvi   Mac Age (min)
+    de:ad:00:00:00:00    1                loop0               2       1       0     1      disabled
+    c2:f6:88:31:7b:8e    1            host-vpp2vpp1           1       0       0     0      disabled
     2 l2fib entries