Docs: Link the Docs + Small Fixes

Change-Id: I7bfec73251d9c271715bbf681c3e9c748321106c
Signed-off-by: Elena Uziunaite <elena.uziunaite@arm.com>
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index baf1fd1..7bf51d8 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -27,6 +27,7 @@
 # The documentation will also be built in a pdf format
 formats:
    - pdf
+   - htmlzip
 
 # Configuration of the Python environment
 python:
diff --git a/docs/conf.py b/docs/conf.py
index baea14f..16da202 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-Tests": ("https://trustedfirmware-m.readthedocs.io/projects/tf-m-tests/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 654fd7a..7e43f65 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -106,6 +106,9 @@
     :hidden:
     :caption: Links
 
+    TF-M Tests <https://trustedfirmware-m.readthedocs.io/projects/tf-m-tests/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/>
     API Reference <https://ci.trustedfirmware.org/job/tf-m-build-docs-nightly/lastSuccessfulBuild/artifact/trusted-firmware-m/build/docs/reference_manual/html/index.html>
     Security Center <https://developer.trustedfirmware.org/w/collaboration/security_center>
     PSA <https://www.arm.com/architecture/security-features/platform-security>