More details view improvements

[mstimberg]

A few cosmetic things we discussed during our meeting:

• the tool name sticks to the top when scrolling
• the link buttons are no longer arranged in three rows, but fill the rows continuously; the three categories (main links, documentation, support) have different button colors
• The "Back to simulators" and "Edit this description on GitHub" button/link have been restored
• The button on the top right can now be used to zoom both in and out

[sanjayankur31]

LGTM