* Add mdbook-linkcheck
* Convert todo to not a link
* Fix external glossary link
* Fix various broken links
* Mass replace: s/.html/.md/
* My sloppy attempt to add a gitlab CI check
* move old implementers' guide, add skeleton of new
* Split the old implementers' guide into the new one's sections
This is mostly a straightforward copying operation, moving the
appropriate sections from the old guide to the new. However, there
are certain differences between the old text and the new:
- removed horizontal rules between the sections
- promoted headers appropriately within each section
- deleted certain sections which were in the old guide's ToC but
which were not actually present in the old guide.
- added Peer Set Manager to the new ToC
* remove description headers
It is redundant and unnecessary. Descriptions fall directly under the
top-level header for any given section.
* add stub description of the backing module
* add stub description for the availability module
* add stub description for collators
* add stub description for validity
* add stub description for utility
* highlight TODO and REVIEW comments
* add guide readme describing how to use mdbook
* fix markdownlint lints
* re-title parachains overview
* internal linking for types
* module and subsystem internal links
* .gitignore should have a trailing newline
* node does not have modules, just subsystems
Sergei Shulepov