Add Eastern Mari layout (#755)

Co-authored-by: Helium314 <helium314@mailbox.org>

app/src/main/assets/language_key_texts/mhr.txt

@@ -0,0 +1,8 @@
+[popup_keys]
+" « » „ “ ”
+н ҥ
+о ӧ
+у ӱ
+
+[labels]
+alphabet: АБВ

app/src/main/assets/layouts/mari.txt

@@ -0,0 +1,44 @@
+ё
+ҥ
+ӧ
+ӱ
+ъ
+-
+!
+?
+"
+/
+
+й
+ц
+у
+к
+е
+н
+г
+ш
+щ
+з
+х
+
+ф
+ы
+в
+а
+п
+р
+о
+л
+д
+ж
+э
+
+я
+ч
+с
+м
+и
+т
+ь
+б
+ю

app/src/main/java/helium314/keyboard/latin/utils/ScriptUtils.kt

@@ -165,7 +165,7 @@ object ScriptUtils {
             "ar", "ur", "fa" -> SCRIPT_ARABIC
             "hy" -> SCRIPT_ARMENIAN
             "bn" -> SCRIPT_BENGALI
-            "sr", "mk", "ru", "uk", "mn", "be", "kk", "ky", "bg", "xdq", "cv" -> SCRIPT_CYRILLIC
+            "sr", "mk", "ru", "uk", "mn", "be", "kk", "ky", "bg", "xdq", "cv", "mhr" -> SCRIPT_CYRILLIC
             "ka" -> SCRIPT_GEORGIAN
             "el" -> SCRIPT_GREEK
             "iw" -> SCRIPT_HEBREW

app/src/main/res/xml/method.xml

@@ -67,6 +67,7 @@
     lo_LA: Lao (Laos)/lao
     lt: Lithuanian/qwerty
     lv: Latvian/qwerty
+    mhr: Mari (Eastern)
     mk: Macedonian/macedonian
     ml_IN: Malayalam (India)/malayalam
     mn_MN: Mongolian (Mongolia)/mongolian
@@ -679,6 +680,15 @@
             android:imeSubtypeMode="keyboard"
             android:imeSubtypeExtraValue="AsciiCapable,EmojiCapable"
             android:isAsciiCapable="true"
+    />
+     <subtype android:icon="@drawable/ic_ime_switcher"
+            android:label="@string/subtype_generic"
+            android:subtypeId="0xb84023bf"
+            android:imeSubtypeLocale="mhr"
+            android:languageTag="mhr"
+            android:imeSubtypeMode="keyboard"
+            android:imeSubtypeExtraValue="KeyboardLayoutSet=mari,SupportTouchPositionCorrection,EmojiCapable"
+            android:isAsciiCapable="false"
     />
     <subtype android:icon="@drawable/ic_ime_switcher"
             android:label="@string/subtype_generic"