Add bookmark support

[alex0809]

The framebuffer frontend does not seem to provide any bookmark support, so this will probably require a custom solution. It might be possible to take inspiration from the existing bookmark implementations of the gtk, atari, and riscos frontends.

[noraatfedora]

The landing page is locally stored - you can just edit the html file and add whatever links you want.

[giovi321]

@noraatfedora cool solution!