Docs: Intersphinx + Error Fix

Linked TF-M documentation using Intersphinx and fixed Sphinx warnings.

Change-Id: Ia27e7a5e1d81959f628e07412f5e4c1493f5f2e7
Signed-off-by: Elena Uziunaite <elena.uziunaite@arm.com>
diff --git a/docs/index.rst b/docs/index.rst
index 9f9bf92..ca85732 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -2,7 +2,6 @@
 Trusted Firmware-M Tests
 ########################
 
-.. raw:: html
 
 The Trusted Firmware-M(TF-M) Tests repo is meant to hold various tests for the
 `Trusted Firmware-M`_.
@@ -28,6 +27,7 @@
   TF-M Extras <https://trustedfirmware-m.readthedocs.io/projects/tf-m-extras/en/latest/>
 
 .. _Trusted Firmware-M: https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/
+
 --------------
 
 *Copyright (c) 2023, Arm Limited. All rights reserved.*
diff --git a/docs/tfm_test_partitions_addition.rst b/docs/tfm_test_partitions_addition.rst
index 8a06171..ba82735 100644
--- a/docs/tfm_test_partitions_addition.rst
+++ b/docs/tfm_test_partitions_addition.rst
@@ -24,7 +24,7 @@
 
 Adding a test partition to provide test services is same as adding a secure
 partition, generally the process can be referenced from the document
-`Adding Secure Partition <https://tf-m-user-guide.trustedfirmware.org/integration_guide/services/tfm_secure_partition_addition.html>`_.
+:doc:`Adding Secure Partition <TF-M:integration_guide/services/tfm_secure_partition_addition>`.
 
 Test Partition Specific Manifest Attributes
 ===========================================
diff --git a/docs/tfm_test_suites_addition.rst b/docs/tfm_test_suites_addition.rst
index b27ed74..9f29518 100644
--- a/docs/tfm_test_suites_addition.rst
+++ b/docs/tfm_test_suites_addition.rst
@@ -69,7 +69,7 @@
 ============================
 
 A test configuration controls whether one or multiple test suites are enabled.
-The doc `TF-M Build Instructions <https://tf-m-user-guide.trustedfirmware.org/technical_references/instructions/tfm_build_instruction.html>`_.
+The doc :doc:`TF-M Build Instructions <TF-M:building/tfm_build_instruction>`.
 shows some test configurations which are already supported in current TF-M.
 An example usage of test configuration shows below.
 
@@ -285,7 +285,7 @@
 Some test group may need specific test services. These test services may support
 one or more groups thus developers shall determine the proper test scope. Refer
 to
-`Adding partitions for regression tests <https://git.trustedfirmware.org/TF-M/tf-m-tests.git/tree/docs/tfm_test_services_addition.rst>`_
+:doc:`Adding partitions for regression tests <tfm_test_partitions_addition>`
 to get more information.
 
 **********************************