Add README_en_Qabs.md (#4594)

buildSrc/src/main/java/org/jackhuang/hmcl/gradle/docs/DocumentLocale.java

@@ -23,11 +23,22 @@ import java.util.Locale;
 /// @author Glavo
 public enum DocumentLocale {
     ENGLISH(Locale.ENGLISH, "") {
+        @Override
+        public String getSubLanguageDisplayName() {
+            return "Standard";
+        }
+
         @Override
         public List<DocumentLocale> getCandidates() {
             return List.of(ENGLISH);
         }
     },
+    ENGLISH_UPSIDE_DOWN(Locale.forLanguageTag("en-Qabs"), "en-Qabs") {
+        @Override
+        public String getSubLanguageDisplayName() {
+            return "uʍoᗡ ǝpᴉsd∩";
+        }
+    },
     SIMPLIFIED_CHINESE(Locale.forLanguageTag("zh-Hans"), "zh"),
     TRADITIONAL_CHINESE("zh-Hant") {
         @Override