feat(username): add aliases option (#5855)

* Create place to put it in the config

* Initial functional version

* Fix grammar

* Add option documentation to README

* Add test for two aliases and emoji translation

* Remove println

* Rewrite match as iflet

* Improve converting the reference

* Format file

* Try to restore autoformat of markdown

* Replace toml:Map with concrete IndexMap

* Update schema

* Add option that got lost

.github/config-schema.json

@@ -1784,6 +1784,7 @@
     },
     "username": {
       "default": {
+        "aliases": {},
         "detect_env_vars": [],
         "disabled": false,
         "format": "[$user]($style) in ",
@@ -6129,6 +6130,13 @@
         "disabled": {
           "default": false,
           "type": "boolean"
+        },
+        "aliases": {
+          "default": {},
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       },
       "additionalProperties": false