Feature: Adds an option in the settings to hide the summary sidebar.

[axeII]

When using Redlib on an iPad or smaller device, I face an issue where the sidebar and summary take up too much space, causing posts to be partially hidden off-screen. I don't really need to read the summary.

To address this, I added a settings option that allows users to completely hide the summary and sidebar, maximizing space for posts, similar to the layout of /r/popular.