[layout] split cblite docs in different files

Markdown generator:

• [x] Read filesystem hierarchy from _20/guides folder.
  Look for files called swift, csharp, objc or java and generate the index page based on the file path.
• [x] Platform switcher.
  Generate the platform tab based on which files are there.
• [x] Content.
  Use the marked module to generate the HTML output.
• [x] Functionality.
  Wrap each file in a <div class="name"></div> element. Add script to allow users to switch tab.

Platform specific content:

• [x] Start/stop replication
• [x] Singleton pattern