Missing hover state in nav

[katjam]

Description

Missing hover state in nav

Steps to reproduce

1. Hover on a nav item - underline does not appear

Acceptance Criteria

• [ ] Hover on a nav item in the header of desktop site - underline does appear
• [ ] Note that it is likely at least one brand has not been updated (see list below). Note also that if it is a phone number and therefor not a link, an underline will not appear
• [ ] www.youmattertoday.org.uk (Haven)
• [ ] www.contemplatingaction.org.uk
• [ ] neontribe.github.io/ca-hospice-hope & https://www.hopestories.org.uk/
• [ ] neontribe.github.io/ca-seap
• [ ] neontribe.github.io/ca-samaritans

Plan

• [x] Replace link text selector class in nav