Qol Patch

[jakima]

I've decided to call this PR a "Quality of Life" patch since it suggests improvements to existing features and some fixes.

• Images are automatically loaded
  • Personally, I think loading images with leading # is good. All the html regarding images is rendered with markdown.js and Javascript could be used to lazy load and resolve images. Nice to have feature when dealing with lots of images.
• All links and images are automatically relative to the directory of a markdown file
  • Sub directory support in other words
  • See subdir_example.md and markdown files under sbd1 for examples
• Full relative linking support with ./ and ../ in paths to refer images and markdown files
  • This would cause an issue where using relative links would pollute page hash with circular(?) references a/../a/b/../ and so on
  • Fixed the same by writing a relative to absolute path resolver
• No need for any special syntax such as # in markdown files
  • Code handles all syntax for a better "out-of-the-box" experience
• Fixed an issue where loadContent would be called more than once on the same page when prettifying hash
• Fixed an issue where a file could be requested out the directory of index.html
• config.root is no longer required
  • This can be tested by starting html server outside the directory of index.html
  • Please consider clearing cache before testing for config.root or use incognito

[arnaudsm]

Thanks a lot for the welcomed improvements! Give me a few days to review

[arnaudsm]

It's hard to review big PRs like this, so I backported some of them into separate branches, and cleaned them up a bit.

• [x] Markdown Image support : Backported into #19
• [x] Scroll position b/w renders : Backported into #20
• [x] Double-fire loadContent : Backported into #21
• [x] Relative linking support : Backported into #25
• [x] Subdirectory support : Already implemented
• [x] No need for # in markdown : Already implemented

These are cool features, thank you very much!