update available languagues for reference doc (git#2127)

## Changes

Add the language names of managed languages in translation of man pages

-

## Context

<!-- Explain why you're making these changes. -->

Author: dscho

data/lang_names.yml

@@ -1,3 +1,4 @@
+cs: "čeština"
 de: "Deutsch"
 en: "English"
 es: "Español"
@@ -8,15 +9,20 @@ id: "Bahasa Indonesia"
 is: "Íslenska"
 it: "Italiano"
 ja: "日本語"
+ko: "한국어"
 mr: "मराठी"
+my: "မျန္မာစာ"
 nb_NO: "Norsk bokmål"
 nl: "Nederlands"
 pl: "Polski"
 pt_BR: "Português (Brasil)"
 pt_PT: "Português (Portugal)"
 ro: "Română"
 ru: "Русский"
+sk: "slovenčina"
+sv: "Svenska"
 tr: "Türkçe"
 uk: "українська мова"
+vi: "Tiếng Việt"
 zh_HANS-CN: "简体中文"
 zh_HANT: "繁體中文"