docs: Documentation restructure

- Change main index structure
- Sort out integration and porting guidelines
- Resort table with releases
- Add Tools section. To be adjusted further for tf-m-tools

Intention to minimise files movement to simplify review process.
Affected files shall be moved later after the new structure agreement.

Signed-off-by: Anton Komlev <anton.komlev@arm.com>
Change-Id: I0352bebabe09d4f7b5e8848ee620c0cea6881c94
diff --git a/docs/technical_references/instructions/tfm_build_instruction.rst b/docs/technical_references/instructions/tfm_build_instruction.rst
index 5e34af5..3db54c4 100644
--- a/docs/technical_references/instructions/tfm_build_instruction.rst
+++ b/docs/technical_references/instructions/tfm_build_instruction.rst
@@ -3,6 +3,14 @@
 ##################
 Please make sure you have all required software installed as explained in the
 :doc:`TF-M getting started </getting_started/tfm_getting_started>`.
+The additional building materials you can find in the following links:
+
+.. toctree::
+    :maxdepth: 1
+
+    IAR toolchain <tfm_build_instruction_iar>
+    Run TF-M examples <run_tfm_examples_on_arm_platforms>
+    Building documentation <documentation_generation>
 
 ****************
 TF-M build steps