feat(markdown-transform): add table transforms

[TC5022]

Signed-off-by: TC5022 [email protected]

Changes

• This is a WIP PR to add table extension in various packages of markdown-transform
• Currently the changes reflect transformations in common mark DOM, HTML, the slate DOM and PDF

Flags

• First we will have to merge the new table models for commonmark and ciceromark for these changes to be successful.

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests
• Commits messages follow AP format
• Extend the documentation, if necessary
• Merging to master from fork:branchname

[coveralls]

Coverage increased (+0.5%) to 86.03% when pulling 51c4ebd on TC5022:TC5022/table-transformations into ac06acd on accordproject:master.

[DianaLease]

This looks great to me! Would like to get @dselman 's review too before merging 👍

[TC5022]

Thanks @DianaLease!

[dselman]

Amazing. Well done!