docs: set up directory for CRD Reference (#800)

docs/content/en/docs/crd-ref/_index.md

@@ -0,0 +1,15 @@
+---
+title: CRD Reference pages
+description: Reference information about the KLT CRDs
+weight: 100
+hidechildren: false # this flag hides all sub-pages in the sidebar-multicard.html
+---
+
+This section provides comprehensive reference information
+about the [Custom Resource Definitions](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/) (CRDs)
+that are defined for the Keptn Lifecycle Toolkit.
+
+**NOTE: This section is under development.
+Information that is published here has been reviewed for technical accuracy
+but the format and content is still evolving.
+We welcome your input!**

docs/content/en/docs/crd-ref/crd-template.md

@@ -0,0 +1,36 @@
+---
+title: <crd-name>
+description: <one-line description of CRD>
+weight: <assign weight to create alphabetical order>
+hide: true
+---
+
+Copy this template to create a new CRD reference page.
+
+1. Replace the variable text in metadata with information for this page
+1. Delete the `hidden: true` line
+1. Delete these instructions from your file
+1. Populate the page with appropriate content
+
+## Synopsis
+```
+```
+
+## Parameters
+
+<Detailed description of each field/parameter>
+
+## Usage
+
+<How this CRD is "activated".  For example, which event uses this CRD>
+<Instructions and guidelines for when and how to customize a CRD>
+
+## Examples
+
+## Files
+
+## Differences between versions
+
+## See also
+
+