Add azure reference docs

Author: r4victor

docs/assets/images/dstack-hub-create-azure-project.png

@@ -24,6 +24,12 @@ For instructions specific to a particular cloud, please refer to the relevant se
 
     [Learn more →](../../reference/backends/aws){ .md-button .md-button--primary }
 
+??? info "Azure"
+    To use Azure, you will require a storage account for storing state and artifacts, as well as Azure AD app credentials
+    to access the corresponding cloud services.
+
+    [Learn more →](../../reference/backends/azure){ .md-button .md-button--primary }
+
 ??? info "GCP"
     To use GCP, you will require a cloud bucket for storing state and artifacts, as well as a
     service account to access the corresponding cloud services.

docs/docs/guides/projects.md

@@ -0,0 +1,55 @@
+# Azure
+
+The `Azure` backend type allows to provision infrastructure and store state and artifacts in
+an Azure account.
+
+Follow the step-by-step guide below to configure a project with this backend.
+
+## 1. Create a resource group
+
+First, create a new Azure resource group. All resource created by `dstack` will belong to this group.
+
+## 2. Create a storage account
+
+Next, create an Azure storage account in the newly created resource group. `dstack` will use this storage account to store metadata and artifacts.
+
+!!! info "NOTE:"
+    Make sure that the storage account is created in the same region where you plan to provision
+    infrastructure.
+
+## 3. Create an Azure Active Directory app 
+
+`dstack` needs an Azure Active Directory app credentials to authenticate with your Azure account. If the app is `Owner` of the subscription, `dstack` will automatically set up all the resources required to run workflows. It will also create a separate managed identity with fine-grained permissions to authenticate with your Azure account when running workflows. 
+
+To create new application credentials using the Azure CLI, run:
+
+```
+az ad sp create-for-rbac --name dstack-app --role Owner --scopes /subscriptions/$SUBSCRIPTION_ID --query "{ client_id: appId, client_secret: password, tenant_id: tenant }"
+```
+
+## 4. Create a project
+
+Now that you have the credentials set up, log in to the Hub, open the `Projects` page, click `Add`, and select `Azure` in
+the `Type` field.
+
+![](../../../assets/images/dstack-hub-create-azure-project.png){ width=800 }
+
+It may take up to a minute to set up Azure resource after saving the project settings.
+
+### Fields reference
+
+The following fields are required:
+
+- `Tenant ID` - (Required) The Azure Tenant ID
+- `Client ID` - (Required) The Client ID to authenticate `dstack`
+- `Client Secret` - (Required) The Client secret to authenticate `dstack`
+- `Subscription ID` - (Required) The Azure Subscription ID
+- `Location` - (Required) The region where `dstack` will create provision infrastructure and store state and artifacts
+- `Storage account` - (Required) The Storage account to store state and artifacts (must be in the same region)
+
+## 5. Configure the CLI
+
+!!! info "NOTE:"
+    Once you have created the project, feel free to use the CLI code snippet to configure it for use with the created project.
+
+    [Learn more →](../../../guides/projects#configuring-the-cli){ .md-button .md-button--primary }

docs/docs/reference/backends/azure.md

@@ -170,6 +170,7 @@ nav:
               - docker: docs/reference/providers/docker.md
           - Backends:
               - AWS: docs/reference/backends/aws.md
+              - Azure: docs/reference/backends/azure.md
               - GCP: docs/reference/backends/gcp.md
   - Examples: https://github.com/dstackai/dstack-examples/blob/main/README.md
   - Slack: https://join.slack.com/t/dstackai/shared_invite/zt-xdnsytie-D4qU9BvJP8vkbkHXdi6clQ