Improving user guide styles.

Adding user guide

Completely remade calculations which greatly improved performance. Also added some new features.

• Satellite positions are now approximated, greatly improving performance.
• Added ability to click on a satellite object to display its interpolated orbit path and some information about the satellite (its name and catalog number).
• Clicking on visible orbit path will hide it.
• Clicking on marked satellite object will unmark it. (Will make the point normal size and remove satellite information label).
• Added ability to track satellites (camera centers on the satellite) by double clicking a satellite object.
• Added satellite search functionality.
• Added ability to toggle fullscreen.
• Added ability to reset camera view to initial position. This also stops tracking (unselects) a satellite object if one is being tracked (is selected).
• Added ability to clear all extra entities (satellite orbits and extra information that was enabled after clicking on satellites).

Initial project. Old code.

• ability to filter (display on/off) satellites by categories.
• ability to control time (forwards/backwards/stopped).
• Very bad performance when satellites are moving.