[Feature]: Sticky Table Headers

[awpala]

What problem does this solve?

When scrolling down the tables, column headers disappears out of view eventually, which loses context for the data rows.

Proposed solution

In routes /schedule and / (main page), make the main tables' respective headers sticky, so that they don't disappear in the page while scrolling down.

Alternatives considered

(N/A)

Additional context

(N/A)