handle default content files

some sections may be applicable to all versions, and it may not make sense to
duplicate the same information across versions as well. this allows a default
file (no -<version> in file name) to be searched for if no version specific
file is found.
prevent consecutive hyphen generation

this fixes an issue where consecutive hyphens are generated in the standard
id method (e.g. C:\ Drive -> c---drive; suppose to be c-drive)
add table of contents link

to go back up to table of contents from each section
adds new line after TODO
adds sections to table of contents