Docs: Link the  Docs + Small Fixes

Change-Id: Ifce633fe50f54b49ffbb5e04e05586503246e54b
Signed-off-by: Elena Uziunaite <elena.uziunaite@arm.com>
diff --git a/docs/conf.py b/docs/conf.py
index 053fb5c..dd8d4c8 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -50,8 +50,17 @@
     'sphinxcontrib.plantuml', #Add support for PlantUML drawings
     'sphinxcontrib.rsvgconverter', #Add support for SVG to PDF
     'sphinx_tabs.tabs', #Enable tab extension in Sphinx
+    'sphinx.ext.intersphinx', #Enable Intersphinx
 ]
 
+intersphinx_mapping = {
+    "TF-M": ("https://trustedfirmware-m.readthedocs.io/en/latest/", None),
+    "TF-M-Tools": ("https://trustedfirmware-m.readthedocs.io/projects/tf-m-tools/en/latest/", None),
+    "TF-M-Extras": ("https://trustedfirmware-m.readthedocs.io/projects/tf-m-extras/en/latest/", None),
+}
+
+intersphinx_disabled_reftypes = ["*"]
+
 # Make auto section labels generated be prefixed with file name.
 autosectionlabel_prefix_document=True
 # Add auto section label for level 2 headers only.
diff --git a/docs/index.rst b/docs/index.rst
index 894dd17..9f9bf92 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -11,7 +11,7 @@
 
 .. toctree::
   :caption: Overview
-  :maxdepth: 1
+  :titlesonly:
   :hidden:
 
   Test Framework <tfm_erpc_test_framework>
@@ -24,6 +24,8 @@
   :hidden:
 
   Trusted Firmware-M <https://trustedfirmware-m.readthedocs.io/en/latest/>
+  TF-M Tools <https://trustedfirmware-m.readthedocs.io/projects/tf-m-tools/en/latest/>
+  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/
 --------------