added environment variables list (Checkmarx#4979)

docs/environment_variables_list.md

@@ -0,0 +1,43 @@
+## Environment Variables List
+
+This document lists all the environment variables that can be used in KICS grouped by their purpose.
+
+
+#### [Environment Variables to fill flags values](https://github.com/Checkmarx/kics/blob/master/docs/configuration-file.md#environment-variables)
+- `KICS_<target_flag>`
+
+
+#### [Terraformer AWS](https://github.com/Checkmarx/kics/blob/master/docs/integrations_terraformer.md#configure-aws-credentials)
+- `AWS_ACCESS_KEY_ID`
+- `AWS_SECRET_ACCESS_KEY`
+- `AWS_SESSION_TOKEN`
+
+
+#### [Terraformer AZURE](https://github.com/Checkmarx/kics/blob/master/docs/integrations_terraformer.md#configure-azure-credentials)
+- `ARM_SUBSCRIPTION_ID`
+- `ARM_CLIENT_ID`
+- `ARM_CLIENT_CERTIFICATE_PATH`
+- `ARM_CLIENT_CERTIFICATE_PASSWORD`
+- `ARM_TENANT_ID`
+
+#### [Terraformer GCP](https://github.com/Checkmarx/kics/blob/master/docs/integrations_terraformer.md#configure-azure-credentials)
+- `GOOGLE_APPLICATION_CREDENTIALS`
+
+
+#### [ASFF report](https://github.com/Checkmarx/kics/blob/master/docs/results.md#asff)
+- `AWS_ACCOUNT_ID`
+- `AWS_REGION`
+
+#### [Decrypt Ansible Vaults on the fly](https://github.com/Checkmarx/kics/blob/master/docs/platforms.md#ansible)
+- `ANSIBLE_VAULT_PASSWORD_FILE`
+
+
+
+#### [Proxy configurations](https://github.com/Checkmarx/kics/blob/master/docs/results.md#descriptions)
+- `HTTP_PROXY`
+- `HTTPS_PROXY`
+- `NO_PROXY`
+
+
+#### [Disable Crash Report](https://github.com/Checkmarx/kics/blob/master/docs/commands.md#disable-crash-report)
+- `DISABLE_CRASH_REPORT`