Update migrated documents where original version has diverged

[eharkins]

It's possible that documents will have been changed, moved, or removed during the process of migration. So to make sure they don't get out of sync with the migrated version, we are tracking the commit of each repository we migrate from, using a branch called migrate-docs on each repository which we are taking docs from. This is a list of those, and a to-do item for going through each repository and ensuring that the original versions of documents in that repository have not diverged from the version migrated, and updating them here if they have diverged. Doing this may be as simple as updating a submodule for some documents (#16).

• ncov (submodule) - https://github.com/nextstrain/ncov/tree/migrate-docs
• nextstrain.org - https://github.com/nextstrain/nextstrain.org/tree/migrate-docs
• augur (submodule & subproject) - https://github.com/nextstrain/augur/tree/migrate-docs
• cli (submodule & subproject) - https://github.com/nextstrain/cli/tree/migrate-docs
• auspice (submodule & subproject) - https://github.com/nextstrain/auspice/tree/migrate-docs

[eharkins]

ncov (submodule) - https://github.com/nextstrain/ncov/tree/migrate-docs
nextstrain.org - https://github.com/nextstrain/nextstrain.org/tree/migrate-docs

These two have no commits on top of their respective master branches and so just need to be updated to the latest commit. All others have pending PRs with commits that allow for them to fit into this project as submodules / subprojects:

Augur: nextstrain/augur#620
CLI: nextstrain/cli#102
Auspice: nextstrain/auspice#1220