Update readme

Author: cmalangone

README.md

@@ -9,6 +9,35 @@ POS will be responsible for:
 * Data validation
 
 
+>**terraform**: Infrastructure deployment for the release. Span off an Elasticsearch Server and loads the data into it.
+
+Eg. deployment_context.tfvars
+```
+config_release_name                     = "pos"
+
+config_gcp_default_region                   = "europe-west1"
+config_gcp_default_zone                     = "europe-west1-d"
+config_project_id                           = "open-targets-eu-dev"
+
+config_gs_etl                               = "open-targets-data-releases/21.04/output"
+
+config_vm_elastic_search_vcpus              = "4"
+config_vm_elastic_search_mem                = "20480"
+config_vm_elastic_search_version            = "7.9.0"
+config_vm_elastic_search_boot_disk_size     = 350
+
+config_vm_pos_machine_type                  = "n1-standard-8"
+config_vm_pos_boot_image                    = "debian-10"
+
+```
+
+Commands:
+```
+gcloud auth application-default login
+terraform init
+terraform plan -var-file="deployment_context.tfvars"
+```
+
 # Copyright
 Copyright 2018-2021 Open Targets