Fixes #1628 numberfield added to .md files;
Fixes #1517
Add brief usage notes for mct-toolbar, WTD-684.
Add documentation for using the mct-form directive introduced for WTD-530.
Add general structure for Open MCT Web, including top-level and second-level directory structure. README files are included to explain the role of each directory; markdown is used to allow for richer display when viewer support is present. WTD-519.