docs: add top level section numbering

Top level sections are not numbered. Adding numbers makes referring to
sections easier. For example the Maintainers page changes from
"about/3.1" to simply "1.3.1".

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: If90a18ee8d6a6858d58f0687f31ea62b69399e04

docs/about/index.rst

@@ -4,7 +4,6 @@ About
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    features
    release-information

docs/components/index.rst

@@ -4,7 +4,6 @@ Components
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    spd/index
    activity-monitors

docs/design/index.rst

@@ -4,7 +4,6 @@ System Design
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    alt-boot-flows
    auth-framework

docs/design_documents/index.rst

@@ -4,7 +4,6 @@ Design Documents
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    cmake_framework
    context_mgmt_rework

docs/getting_started/index.rst

@@ -4,7 +4,6 @@ Getting Started
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    prerequisites
    docs-build

docs/index.rst

@@ -3,7 +3,7 @@ Trusted Firmware-A Documentation
 
 .. toctree::
    :maxdepth: 1
-   :hidden:
+   :numbered:
 
    Home<self>
    about/index

docs/perf/index.rst

@@ -4,7 +4,6 @@ Performance & Testing
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    psci-performance-juno
    tsp

docs/plat/index.rst

@@ -4,7 +4,6 @@ Platform Ports
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
    :hidden:
 
    allwinner

docs/process/index.rst

@@ -4,7 +4,6 @@ Processes & Policies
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    security
    platform-ports-policy

docs/security_advisories/index.rst

@@ -4,7 +4,6 @@ Security Advisories
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    security-advisory-tfv-1.rst
    security-advisory-tfv-2.rst

docs/threat_model/index.rst

@@ -11,7 +11,6 @@ based on the data flow diagram and potential threat mitigations.
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    threat_model
    threat_model_spm