A lot of changes :)

[pduchnovsky]

• Inspired by @yukimuon, added theme color customization
• Changed readme to reflect new features
• Added LinkedIn icon and changed code so when one of the links variables are not in config the icon is hidden
• Changed Headings size in general to follow normal blog-like sizes
• Added Aria Labels to conform with Google recommendations in relation to accessibility
• Changed prismjs theme to more modern version - VS Code Dark+ (by tabuckner)
• Prism line numbers reduced padding so there is more space for actual code
• Fixed/changed the way of handling icon links and rest below..

[adisaktijrs]

Hi, these are a lot of changes and I love it! You guys are amazing. I don't really review all of these codes tbh. I notice about the sitemap option issue as @yukimuon mentioned and then it's already fixed at 045c0fe7edb86a651e263242f2ac565a414182f9. Therefore I think everything is going fine. I am new at managing open source so bear w/ me hehe. Thank you in advance!