Lumosviridi v20 kubernetes updates (#6356)

Updates for v20+ and misc terraform bug fixes. Also refactored to use
terraform variables instead of locals which helps with readability and
ease of use for new users.

Terraform validation is currently passing:
![Screenshot 2024-07-21 at 13 18
37](https://github.com/user-attachments/assets/02aadc2d-d3f6-4e8b-9315-64e25191d9e6)

Additionally added [terraform-docs](https://terraform-docs.io/) to
generate a more helpful README for terraform specific configuration.

Raw K8s manifests were updated with changes for v20+ as well.

---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>

packages/twenty-docker/k8s/terraform/namespace.tf

@@ -1,9 +1,9 @@
 resource "kubernetes_namespace" "twentycrm" {
   metadata {
     annotations = {
-      name = "twentycrm"
+      name = var.twentycrm_namespace
     }
 
-    name = "twentycrm"
+    name = var.twentycrm_namespace
   }
 }