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/
+
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