Add Blender Dev Container Template information (devcontainers#638)

* Add Blender Dev Container Template information

* Update OCI reference for Blender Dev Container

* Fix formatting of repository URL in collection-index.yml

Author: katohirosato

_data/collection-index.yml

@@ -1356,3 +1356,8 @@
   contact: https://github.com/roboslone/go-framework/issues
   repository: https://github.com/roboslone/go-framework/tree/main/src/fexec
   ociReference: ghcr.io/roboslone/go-framework
+- name: Blender Dev Container Template for Extension development
+  maintainer: peakys (@katohirosato)
+  contact: https://github.com/peakys-org/blender-devcontainer/issues/
+  repository: https://github.com/peakys-org/blender-devcontainer/
+  ociReference: ghcr.io/peakys-org/blender-devcontainer/blender-devcontainer