feat(azure): subscription name aliases (#4949)

* From issue #4448, added `subscription_aliases`
as a field for the Azure module

Can be set in starship.toml with
[azure.subscription_aliases]

* Updated config file schema

* Added entry into documentation

* Update README.md

* Formatted with dprint

.github/config-schema.json

@@ -29,6 +29,7 @@
         "disabled": true,
         "format": "on [$symbol($subscription)]($style) ",
         "style": "blue bold",
+        "subscription_aliases": {},
         "symbol": "ﴃ "
       },
       "allOf": [
@@ -1849,6 +1850,13 @@
         "disabled": {
           "default": true,
           "type": "boolean"
+        },
+        "subscription_aliases": {
+          "default": {},
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       },
       "additionalProperties": false