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/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::