i18n (internationalization)

> _As a **person build web applications/sites** in **various languages**_
> I need a way to (_easily_) **translate** the app/site into different

On the Phoenix Framework Website docs http://www.phoenixframework.org/docs/
there isn't an _obvious_ page for _internationalisation_ ... so it's _unclear_ how we should go about making our _english_ web application/site

> If you are _totally_ `new` to **internationalization** (i18n)
read: https://www.w3.org/International/questions/qa-i18n

Searching the Phoenix Framework site for `i18n` we see no results:

But there _appears_ to be a result when searching for the _full_ word `internationalization`:

The link is to:
http://www.phoenixframework.org/blog/phoenix-10-the-framework-for-the-modern-web-just-landed
Which _includes_ the word (_so we know the full-text search is working..._) but is kinda useless:
The "What's Next" section of the Phoenix 1.0 announcement
http://www.phoenixframework.org/blog/phoenix-10-the-framework-for-the-modern-web-just-landed#whats-next
Does not go into _any_ detail of ***how*** to _implement_ i18n in a Phoenix app.

A bit of Googling returns these two posts:

+ (_Old but still_) seems relevant: http://sevenseacat.net/posts/2015/i18n-in-phoenix-apps
+ Using Gettext to internationalize a Phoenix app: http://blog.plataformatec.com.br/2016/03/using-gettext-to-internationalize-a-phoenix-application (_platformatec is where Jose Valim works so should be a good place to start_)

## Todo:

+ [ ] [SPIKE] Try a basic "Hello World" in 2 languages using the `Gettext` method
+ [ ] Write it up in a step-by-step guide.