A quick guide to multilingual blog using Hugo with PaperMod theme

Basically a short summary of what I had to dig for in the process of giving this site a go.

A note: I prefer to use YAML for Hugo configuration because TOML is less useable for nested structures like menu configuration and JSON is a bit less human-readable in general. A default format for front matter of content created with hugo new command can be set by modifying the template archetypes/default.md.

Do a regular i18n setup in Hugo project configuration:
```
defaultContentLanguage: en
defaultContentLanguageInSubdir: false
params.displayFullLangName: false
```
params.displayFullLangName: false tells PaperMod theme to use capitalized 2-letter language ID as a language name in selector.

Translate the main menu.

An example:

languages:
    en:
        weight: 10
        languageName: English
        menu:
        main:
            -
            weight: 10
            name: Posts
            pageRef: /posts
            -
            weight: 20
            name: Tags
            pageRef: /tags
            -
            weight: 30
            name: Categories
            pageRef: /categories
            -
            weight: 40
            name: Search
            pageRef: /search
    ru:
        weight: 20
        languageName: Русский
        menu:
        main:
            -
            weight: 10
            name: Посты
            title: Посты
            pageRef: /posts
            -
            weight: 20
            name: Теги
            title: Теги
            url: /tags
            -
            weight: 30
            name: Категории
            title: Категории
            pageRef: /categories
            -
            weight: 40
            name: Поиск
            title: Поиск
            pageRef: /search

Add JSON to generated output to make the search able to work:
```
outputs:
    home: [HTML, RSS, JSON]
```
Add a translation for «Posts» page: create content/_index.<language ID>.md and put a translation of the word «posts» into title field of the front matter.

An example:

content/_index.ru.md
```
---
title: Посты
---
```

Add «Search» page content/search.md and its translation(s) named content/search.<language ID>.md.

An example:

content/search.md:

---
title: Search
layout: search
summary: Search
placeholder: Search the site
---

content/search.ru.md:

---
title: Поиск
layout: search
summary: Страница поиска по сайту
placeholder: Поиск по сайту
---

Add translations for blog utility pages i. e. «Tags», «Categories» and «Search»: create content/categories.<language ID>.md, content/tags.<language ID>.md and content/search.<language ID>.md. Basically a front matter with only title field is enough.
Add posts in default language named like posts/some-new-post.md and corresponding translations named like posts/some-new-post.<language ID>.md.