Fix member link to team page is sometimes wrong

This fixes an inconsistency among member links to the team page by replacing the usage of .slug with anchroize .gitlab:

Right now, the link’s anchor is taken from the member’s slug. But the anchor on the team page (layouts/shortcodes/team.html) is taken from the gitlab name and then also sanitized with anchorize.

An example is Nao’s link on Engineering Productivity team page, which contains a dot (nao.hashizume) that is removed by anchorize (naohashizume), leading to the inconsistency.