Adding dunfell 3.1.7 to the switcher and release list.

(From yocto-docs rev: bed221137de77340280d71b4a8b0f2f60addc566)

Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/releases.rst

@@ -30,6 +30,7 @@
 - :yocto_docs:`3.1.4 Documentation </3.1.4>`
 - :yocto_docs:`3.1.5 Documentation </3.1.5>`
 - :yocto_docs:`3.1.6 Documentation </3.1.6>`
+- :yocto_docs:`3.1.7 Documentation </3.1.7>`
 
 ==========================
  Previous Release Manuals

documentation/sphinx-static/switchers.js

@@ -5,7 +5,7 @@
     'dev': 'dev (3.4)',
     '3.3': '3.3',
     '3.2.3': '3.2.3',
-    '3.1.6': '3.1.6',
+    '3.1.7': '3.1.7',
     '3.0.4': '3.0.4',
     '2.7.4': '2.7.4',
   };