Add intersphinx

Add sphinx extension for allowing internals documentation
to refer to main Tarantool documentation.

Resolves #6

Author: ImeevOchir

source/conf.py

@@ -40,6 +40,7 @@
 # ones.
 extensions = [
     'recommonmark',
+    'sphinx.ext.intersphinx',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
@@ -160,5 +161,13 @@
      'Miscellaneous'),
 ]
 
+# -- Mapping for Intersphinx -------------------------------------------------
+
+intersphinx_mapping = {
+    'community': (
+        "https://www.tarantool.io/en/doc/latest",
+        "community.inv"
+    )
+}
 
 # -- Extension configuration -------------------------------------------------