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/design_docs/index.rst b/docs/technical_references/design_docs/index.rst
index 3566e03..bdd2d03 100644
--- a/docs/technical_references/design_docs/index.rst
+++ b/docs/technical_references/design_docs/index.rst
@@ -1,4 +1,4 @@
-Design documents
+Design Documents
 ================
 
 .. toctree::
diff --git a/docs/technical_references/index.rst b/docs/technical_references/index.rst
deleted file mode 100644
index 200d469..0000000
--- a/docs/technical_references/index.rst
+++ /dev/null
@@ -1,13 +0,0 @@
-Technical References
-====================
-
-.. toctree::
-    :maxdepth: 2
-    :titlesonly:
-    :glob:
-
-    */index
-
---------------
-
-*Copyright (c) 2020-2021, Arm Limited. All rights reserved.*
diff --git a/docs/technical_references/instructions/documentation_generation.rst b/docs/technical_references/instructions/documentation_generation.rst
index b99b0b1..44ed546 100644
--- a/docs/technical_references/instructions/documentation_generation.rst
+++ b/docs/technical_references/instructions/documentation_generation.rst
@@ -154,9 +154,9 @@
 
             # Command line tools is yet not available for Windows
 
-############
+************
 Dependencies
-############
+************
 
 .. uml::
 
diff --git a/docs/technical_references/instructions/index.rst b/docs/technical_references/instructions/index.rst
deleted file mode 100644
index 6e869ee..0000000
--- a/docs/technical_references/instructions/index.rst
+++ /dev/null
@@ -1,15 +0,0 @@
-TF-M Detailed Instructions
-==========================
-
-.. toctree::
-    :maxdepth: 1
-    :glob:
-
-    tfm_build_instruction
-    tfm_build_instruction_iar
-    run_tfm_examples_on_arm_platforms
-    documentation_generation
-
---------------
-
-*Copyright (c) 2021, Arm Limited. All rights reserved.*
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