add dns resolver settings (#18669)

Author: necusjz

specification/dnsresolver/resource-manager/readme.az.md

@@ -0,0 +1,52 @@
+# AZ
+
+These settings apply only when `--az` is specified on the command line.
+
+``` yaml $(az)
+az:
+    extensions: dns-resolver
+    namespace: azure.mgmt.dnsresolver
+    package-name: azure-mgmt-dnsresolver
+az-output-folder: $(azure-cli-extension-folder)/src/dns-resolver
+python-sdk-output-folder: "$(az-output-folder)/azext_dnsresolver/vendored_sdks/dnsresolver"
+
+# add additional configuration here specific for Azure CLI
+# refer to the faq.md for more details
+extension-mode: preview
+
+cli:
+  cli-directive:
+# rename command groups
+    - where:
+        group: 'DnsForwardingRulesets'
+      name: 'forwarding_rulesets'
+    - where:
+        group: 'VirtualNetworkLinks'
+      name: 'vnet_links'
+# rename commands
+    - where:
+        group: 'DnsResolvers'
+        op: 'ListByVirtualNetwork'
+      name: 'list'
+    - where:
+        group: 'DnsForwardingRulesets'
+        op: 'ListByVirtualNetwork'
+      name: 'list'
+# add alias to parameters
+    - where:
+        group: ForwardingRules
+        parameter: dnsForwardingRulesetName
+      alias:
+        - ruleset_name
+    - where:
+        group: VirtualNetworkLinks
+        parameter: dnsForwardingRulesetName
+      alias:
+        - ruleset_name
+    - where:
+        group: DnsForwardingRulesets
+        op: CreateOrUpdate#Create
+        parameter: dnsResolverOutboundEndpoints
+      alias:
+        - outbound_endpoints
+```