Update form ux

Instructions:

- Instead of showing all fields at once (like 8 input fields in the Skills tab) show either 1 or 2 and add buttons to add a field.
- Add a delete icon on each field to delete the field if added by mistake.
- Accept input for repository URLs that users want to show in their portfolio.
- Make GitHub access token optional and ask it only if the user enters any repository URL that is private.

Start by locating the Skills tab form and the inputs for repository URLs and GitHub access tokens. Review how fields are currently rendered and how repository access is handled; done means fields can be added and deleted, public URLs are accepted without a token, and a token is requested only for private repositories.

Written by the indexing model from the issue text.