docs: add orderedByFrequency to the language adding guide

Author: Miodec

docs/LANGUAGES.md

@@ -22,13 +22,14 @@ The contents of the file should be as follows:
   "name": string,
   "rightToLeft": boolean,
   "ligatures": boolean,
+  "orderedByFrequency": boolean,
   "bcp47": string,
   "words": string[]
 }
 ```
 
 It is recommended that you familiarize yourselves with JSON before adding a language. For the `name` field, put the name of your language. `rightToLeft` indicates how the language is written. If it is written right to left then put `true`, otherwise put `false`.
-`ligatures` A ligature occurs when multiple letters are joined together to form a character [more details](<https://en.wikipedia.org/wiki/Ligature_(writing)>). If there's joining in the words, which is the case in languages like (Arabic, Malayalam, Persian, Sanskrit, Central_Kurdish... etc.), then set the value to `true`, otherwise set it to `false`. For `bcp47` put your languages [IETF language tag](https://en.wikipedia.org/wiki/IETF_language_tag). Finally, add your list of words to the `words` field.
+`ligatures` A ligature occurs when multiple letters are joined together to form a character [more details](<https://en.wikipedia.org/wiki/Ligature_(writing)>). If there's joining in the words, which is the case in languages like (Arabic, Malayalam, Persian, Sanskrit, Central_Kurdish... etc.), then set the value to `true`, otherwise set it to `false`. For `bcp47` put your languages [IETF language tag](https://en.wikipedia.org/wiki/IETF_language_tag). If the words you're adding are ordered by frequency (most common words at the top, least at the bottom) set the value of `orderedByFrequency` to `true`, otherwise `false`.  Finally, add your list of words to the `words` field.
 
 In addition to the language file, you need to add your language to the `_groups.json` and `_list.json` files in the same directory. Add the name of the language to the `_groups.json` file like so: