Update About page (roadmap)

[edhamiltonHO]

Which content do you think should be reviewed? The about page - https://engineering.homeoffice.gov.uk/about/

Why do you think we should review this? A number of the items in the roadmap have now been completed

Do you have a suggestion for how this could be improved? Outline a longer term roadmap so that needs updating less frequently

Please confirm the below

• [ ] I have checked through the issues on the repository and don't think this has already been suggested