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
diff --git a/docs/about/index.rst b/docs/about/index.rst
index 3a10266..06973ef 100644
--- a/docs/about/index.rst
+++ b/docs/about/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    features
    release-information
diff --git a/docs/components/index.rst b/docs/components/index.rst
index 0972a68..30d80fc 100644
--- a/docs/components/index.rst
+++ b/docs/components/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    spd/index
    activity-monitors
diff --git a/docs/design/index.rst b/docs/design/index.rst
index e3b8f74..17ef756 100644
--- a/docs/design/index.rst
+++ b/docs/design/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    alt-boot-flows
    auth-framework
diff --git a/docs/design_documents/index.rst b/docs/design_documents/index.rst
index 765efe6..3e20c07 100644
--- a/docs/design_documents/index.rst
+++ b/docs/design_documents/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    cmake_framework
    context_mgmt_rework
diff --git a/docs/getting_started/index.rst b/docs/getting_started/index.rst
index 7171303..3fbf48d 100644
--- a/docs/getting_started/index.rst
+++ b/docs/getting_started/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    prerequisites
    docs-build
diff --git a/docs/index.rst b/docs/index.rst
index edc2535..3860199 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -3,7 +3,7 @@
 
 .. toctree::
    :maxdepth: 1
-   :hidden:
+   :numbered:
 
    Home<self>
    about/index
diff --git a/docs/perf/index.rst b/docs/perf/index.rst
index 1482b80..bccad00 100644
--- a/docs/perf/index.rst
+++ b/docs/perf/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    psci-performance-juno
    tsp
diff --git a/docs/plat/index.rst b/docs/plat/index.rst
index 3eac6f7..a4e2067 100644
--- a/docs/plat/index.rst
+++ b/docs/plat/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
    :hidden:
 
    allwinner
diff --git a/docs/process/index.rst b/docs/process/index.rst
index 422ab28..7914a4e 100644
--- a/docs/process/index.rst
+++ b/docs/process/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    security
    platform-ports-policy
diff --git a/docs/security_advisories/index.rst b/docs/security_advisories/index.rst
index 887b06a..b80ba34 100644
--- a/docs/security_advisories/index.rst
+++ b/docs/security_advisories/index.rst
@@ -4,7 +4,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    security-advisory-tfv-1.rst
    security-advisory-tfv-2.rst
diff --git a/docs/threat_model/index.rst b/docs/threat_model/index.rst
index 9d84f5b..ad8b82a 100644
--- a/docs/threat_model/index.rst
+++ b/docs/threat_model/index.rst
@@ -11,7 +11,6 @@
 .. toctree::
    :maxdepth: 1
    :caption: Contents
-   :numbered:
 
    threat_model
    threat_model_spm