docs migration: Container Lifecycle Hooks into Concepts (#2564)

* initial commit for structure

* migrate Container Lifecycle Hooks and related files to Concepts

* update Concepts ToC

* fix formatting

* Formatting tweaks

* comment out What's next

* remove What's next

* Begin rewrite of container-lifecycle-hooks.md

* incremental update to edit

* Split Container Lifecycle Hooks into container-lifecycle-hooks.md and container-environment.md; change all referring links.

* Add concept template to volumes.md and images.md

* Apply changes for steveperry-53 feedback.

* fix format issue

* tweak formatting

* fix Concepts ToC

* update links

* add back changes to Concepts ToC

* fix a link

* update links

docs/concepts/storage/volumes.md

@@ -7,18 +7,22 @@ assignees:
 title: Volumes
 ---
 
+{% capture overview %}
+
 On-disk files in a container are ephemeral, which presents some problems for
 non-trivial applications when running in containers.  First, when a container
-crashes kubelet will restart it, but the files will be lost - the
+crashes, kubelet will restart it, but the files will be lost - the
 container starts with a clean state.  Second, when running containers together
 in a `Pod` it is often necessary to share files between those containers.  The
 Kubernetes `Volume` abstraction solves both of these problems.
 
 Familiarity with [pods](/docs/user-guide/pods) is suggested.
 
-* TOC
+{% endcapture %}
+
 {:toc}
 
+{% capture body %}
 
 ## Background
 
@@ -626,3 +630,7 @@ In the future, we expect that `emptyDir` and `hostPath` volumes will be able to
 request a certain amount of space using a [resource](/docs/user-guide/compute-resources)
 specification, and to select the type of media to use, for clusters that have
 several media types.
+
+{% endcapture %}
+
+{% include templates/concept.md %}