Docs: Add information about TF-M repositories

Signed-off-by: Awadhy Mohammed <awadhy.mohammed@arm.com>
Change-Id: I2e2ceaea11b394dc1c9198201cb7f589303304ed
diff --git a/docs/introduction/readme.rst b/docs/introduction/readme.rst
index 82559cf..31cc765 100644
--- a/docs/introduction/readme.rst
+++ b/docs/introduction/readme.rst
@@ -49,6 +49,27 @@
 refer to ``Trusted Firmware M.`` :doc:`Glossary </glossary>` has the list
 of terms and abbreviations.
 
+************
+Repositories
+************
+
+TF-M is comprised of multiple repositories that supplement each other in making the project both customisable and maintainable.
+
+.. list-table:: TF-M Repositories
+    :widths: auto
+    :header-rows: 1
+
+    * - **Repository**
+      - **Description**
+    * - `trusted-firmware-m <https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/tree/>`_
+      - Software implementation of TF-M with documentation and essential tools
+    * - `tf-m-tests <https://git.trustedfirmware.org/TF-M/tf-m-tests.git/tree/>`_
+      - Tests that focus on the functionalities of TF-M components
+    * - `tf-m-tools <https://git.trustedfirmware.org/TF-M/tf-m-tools.git/tree/>`_
+      - Non essential tools used for testing and verification of TF-M
+    * - `tf-m-extras <https://git.trustedfirmware.org/TF-M/tf-m-extras.git/tree/>`_
+      - Extension of the main repository to host examples, demonstrations, third-party modules etc
+
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 License
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