A `block` marks a span of template content. It has an identifier. If the block
isn't referenced anywhere else, nothing special happens and the contents are
simply output.

#### Example 1
{% block myblock %}Like so my block{% endblock %}

A `block` can share it's identifier, but this is more often than not a mistake :)

#### Example 2
{% block myblock %}Like this is so my other block{% endblock %}

On it's own a `block`s contents are rendered as given into the template output.
Only in conjunction with [`extends`](extends.scion?wrapper=_wrapper.scion) does
the `block` reveal its true usefulness.

Can `block`/`endblock` be used in multi-line statements ? Preferably not.