Moved more site content to content repo and added dynamic feeds/maps

[obany]

• Header content moved to documentation site-settings folder

• Footer content moved to documentation site-settings folder

• Added view options to documentation site-settings folder

• Home page image assets moved to documentation site-settings/assets folder

• Added dynamic feeds which can retrieve data from the api using a context and display it, supports paging and builds dynamic table of contents based on the h2 content rendered

• Feeds currently only support eventbrite/events

• Added maps support for markdown

• Markdown usage for feeds and maps https://github.com/iotaledger/documentation/pull/170/files

To enable a feed on the api you must configure its options in the api:

{
    "feeds": {
        "training": {
            "service": "eventbrite",
            "config": {
                "oauthToken": "ABCDEFGHIGKJL"
            }
        }
    }
}

The feed would then be available as https://docs-api.iota.org/feed/training?page=0&pageSize=5

To use event or maps you need to specify a google maps key in the app config.

{
  "googleMapsKey": "AIzaSyCt8FGUABCDEFGHEh5etKjrZWUF7YYLs"
}