Issue Overview

In the template documentation there is no information what attributes can be used for the different blocks.

'template' => array(
    array( 'core/image', array(
        'align' => 'left',
    ) ),
),

https://wordpress.org/gutenberg/handbook/templates/

Possible Solution

The attributes can be found in the index.js of the the single blocks which can be found in https://github.com/WordPress/gutenberg/blob/master/blocks/library/

The path for the index.js would https://github.com/WordPress/gutenberg/blob/{block-name}/index.js

The current attributes for the paragraph block currently are

const {
    align,
    content,
    dropCap,
    placeholder,
    backgroundColor,
    textColor,
    width,
} = attributes;

which can be found here: https://github.com/WordPress/gutenberg/blob/v2.6.0/blocks/library/paragraph/index.js#L139-L145

Todos

• Documentation