Include all subsection format classes w/ cross-links

[kg583]

Currently, the wiki only documents children of TIEntry. This needs to be expanded to include any and all classes that describe subsection formats, such as enums (e.g. gdb/GraphColor), flags (e.g. numeric/FloatFlags), and certain non-obvious converters (e.g. numeric/BCD).

All subsection formats, meanwhile, need cross-links to their definitions.