add aria-labels to h1 tags which contain SVG text

[aaaaargZombies]

Fixes #342

Description

• add aria-labels to h1 tags and a tags that that use the svg logo

https://developer.mozilla.org/en-US/docs/Web/Accessibility/Understanding_WCAG/Text_labels_and_names#headings_should_have_visible_text_content

It looks like the use of SVG logos instead of a text node is not advised for headers so this will be unlikely to meet WCAG standards. Aria-label is not a substitute, but seeing as this is a core part of the sites design it seems unlikely that we will rework this in the near future. This at least provides screen readers with information when they hit the header for navigation.

https://amberwilson.co.uk/blog/are-your-anchor-links-accessible/#a-word-of-caution

This also suggests that there are issues with adding links and images into headers but that is beyond the scope of this issue.

[aaaaargZombies]

I'm going to come back to this and put text in that is hidden from eyes and set the images to aria-hidden