🚸 Set "Portfolio-level overview" as the default starting tab

[jdhoffa]

Currently, the dashboard starts with an Introduction tab/page, which is redundant since users have already uploaded their portfolio and generated a report. By this point, they are familiar with PACTA. Starting with the "Portfolio-level overview" tab would eliminate an unnecessary hurdle and provide immediate access to results.

Also, it is more of an "About PACTA" page than an "Introduction"