Fix build warnings

Author: patiencedaur

doc/book/replication/repl_sync.rst

@@ -1,4 +1,5 @@
 ..  _internals-replication-orphan_status:
+..  _replication-orphan_status:
 
 Orphan status
 =============

doc/dev_guide/internals/replication/orphan.rst

@@ -1,4 +1,4 @@
-.. _datetime_object:
+.. _datetime_obj:
 
 datetime_object
 ===============
@@ -249,7 +249,7 @@ datetime_object
 
         Modify an existing datetime object by adding values of the input argument.
 
-        :param table input: an :ref:`interval object <interval-new>` or an equivalent table (see **Example #1**)
+        :param table input: an :ref:`interval object <interval_obj>` or an equivalent table (see **Example #1**)
         :param string adjust: defines how to round days in a month after an arithmetic operation.
                                 Possible values: ``none``, ``last``, ``excess`` (see **Example #2**). Defaults to ``none``.
 
@@ -340,7 +340,7 @@ datetime_object
 
         Modify an existing datetime object by subtracting values of the input argument.
 
-        :param table input: an :ref:`interval object <interval-new>` or an equivalent table (see **Example**)
+        :param table input: an :ref:`interval object <interval_obj>` or an equivalent table (see **Example**)
         :param string adjust: defines how to round days in a month after an arithmetic operation.
                                 Possible values: ``none``, ``last``, ``excess``. Defaults to ``none``.
                                 The logic is similar to the one of the ``:add()`` method -- see :ref:`Example #2 <datetime-add-example2>`.

doc/reference/reference_lua/datetime/datetime_object.rst

@@ -1,6 +1,6 @@
-.. _inverval_object:
+.. _interval_obj:
 
-inverval_object
+interval_object
 ===============
 
 ..  class:: interval_object

doc/reference/reference_lua/datetime/interval_object.rst

@@ -13,7 +13,7 @@ datetime.new()
     :param table units: Table of :ref:`time units <datetime-new-args>`.
                                 If an empty table or no arguments are passed, the ``datetime`` object with the default values corresponding to Unix Epoch is created: ``1970-01-01T00:00:00Z``.
 
-    :return: :doc:`datetime object <./datetime/datetime_object>`
+    :return: :ref:`datetime object <datetime_obj>`
     :rtype: cdata
 
     ..  _datetime-new-args:

doc/reference/reference_lua/datetime/new.rst

@@ -44,7 +44,7 @@ Incompatible changes:
     Please update your client libraries if you plan to use these new features
     (:tarantool-issue:`2802`).
   * :ref:`fiber_name() <fiber_object-name_get>` now raises an exception instead of truncating long fiber names.
-    We found that some Lua modules such as :ref:`expirationd <expirationd-module>` use ``fiber.name()``
+    We found that some Lua modules such as `expirationd <https://tarantool.github.io/expirationd/>`_ use ``fiber.name()``
     as a key to identify background tasks. If a name is truncated, this fact was
     silently missed. The new behavior allows to detect bugs caused by ``fiber.name()``
     truncation. Please use ``fiber.name(name, { truncate = true })`` to emulate