As a visitor to the ATT&CK website, I want to see mitigation IDs when looking at the mitigation tables on technique pages.

Note: the ID should not be added just as a column, because some users may interpret this as the ID of the mapping itself, and not of the attached object. One possible solution would be to have it as a tooltip on the object name, although it would probably be better to have it visible without the user needing to mouse-over.

See also #236.