Add Breadcrumbs to any non-included page #M2 From http://www.webmull.com/magento-2-add-new-custom-breadcrumb-in-checkout-page/
<referenceBlock name="breadcrumbs">
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">Home</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">Home</item>
<item name="label" xsi:type="string">Home</item>
<item name="link" xsi:type="string">/</item>
</argument>
</action>
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">Shopping Cart</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">Shopping Cart</item>
<item name="label" xsi:type="string">Shopping Cart</item>
<item name="link" xsi:type="string">/checkout/cart</item>
</argument>
</action>
</referenceBlock>
In ptemplate file:
<?php echo $this->getLayout()->getBlock('breadcrumbs')->toHtml(); ?>