Fix Google docs links in README

[bact]

• Fix Markdown for links to "Draft document" and "Reference document" (currently lead to "Bad Request" page)
• Fix typo: "Reference doument" -> "Reference document"
• Also fix inconsistencies in Markdown format (not effecting content)
  • MD004 - Unordered list style (use both * and - in the same document)
  • MD006 - Consider starting bulleted lists at the beginning of the line
  • MD012 - Multiple consecutive blank lines
  • MD022 - Headers should be surrounded by blank lines
  • MD047 - File should end with a single newline character