Improve consitency of link captialisation and evaluate links

The captilisation used for further links is inconsistent. There are also a
rather large number of links under "Developer Ready".

Reduce captitalisation for the further links items, re-order and reduce
the number of further links under "Developer Ready" to focus more on the
important topics not linked elsewhere.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/_index.md

@@ -38,8 +38,8 @@ Apertis undergoes regular [automated and manual testing](https://qa.apertis.org)
 
 ## Further Links
 
-* [Policy Documentation]( {{< ref "policies" >}} )
-* [Quality Assurance]( {{< ref "/qa/_index.md" >}} )
+* [Policy documentation]( {{< ref "policies" >}} )
+* [Quality assurance]( {{< ref "/qa/_index.md" >}} )
 * [Test results](https://lavaphabbridge.apertis.org)
 
 
@@ -57,7 +57,7 @@ For more information, see [Release flow and product lines]( {{< ref "release-flo
 * Current stable release: [v2020.1]( {{< ref "/release/v2020.1/releasenotes.md" >}} )
 * Current old stable release: [v2019.3]( {{< ref "/release/v2019.3/releasenotes.md" >}} )
 * Current development release: [v2021dev2]( {{< ref "/release/v2021dev2/releasenotes.md" >}} )
-* [Further Releases]( {{< ref "releases.md" >}} )
+* [Further releases]( {{< ref "releases.md" >}} )
 
 
 # Developer Ready
@@ -69,13 +69,11 @@ Apertis provides a number of pre-built images for Intel (64-bit) and ARM (32-bit
 
 ## Further Links
 
-* [Code of conduct]( {{< ref "/code_of_conduct.md" >}} )
-* [Download the current images]( {{< ref "/images.md" >}} )
+* [Download the current images]( {{< ref "images.md" >}} )
 * [Source code](https://gitlab.apertis.org)
-* [Mailing lists](https://lists.apertis.org/)
-* [Architectural documentation]( {{< ref "/architecture" >}}) 
-* [Development guides]( {{< ref "/guides" >}} )
-* [Concept designs]( {{< ref "concepts" >}} )
+* [Architectural documentation]( {{< ref "architecture" >}}) 
+* [Development guides]( {{< ref "guides" >}} )
 * [Design documents]( {{< ref "designs" >}} )
+* [Concept designs]( {{< ref "concepts" >}} )
 * [Supported APIs](https://developer.apertis.org/latest/apis.html)
 * [App developer portal](https://developer.apertis.org)