Fix validation errors.

This is minor stuff to fix validation errors (against HTML5); I used http://html5.validator.nu/ to check and the changes seemed reasonable enough to me to include:

- The `rel` with value `"coleslaw"` is invalid and it seems something like `"made"` is no better. To identify the element `id` can be used, which also fixes
- the issue that `align` shouldn't be used in favour of CSS;
- and images need to have an `alt` attribute.

Cheers,
Olof