feat: add nils-geistmann devcontainer features (#404)

Author: nils-geistmann

_data/collection-index.yml

@@ -778,3 +778,8 @@
   contact: https://github.com/m4tchl0ck/devcontainer-features/issues
   repository: https://github.com/m4tchl0ck/devcontainer-features/
   ociReference: ghcr.io/m4tchl0ck/devcontainer-features
+- name: Dev Container Features by nils-geistmann
+  maintainer: Nils Geistmann
+  contact: https://github.com/nils-geistmann/devcontainers-features/issues
+  repository: https://github.com/nils-geistmann/devcontainers-features/
+  ociReference: ghcr.io/nils-geistmann/devcontainers-features