* Add table examples

* Add table types and adopt simple parser

Simple parser is done by Giovanni Cappellotto (@potomak)
in https://github.com/haskell/haddock/pull/577
It seems to support single fine full tables, so far from full
RST-grid tables, but it's good start.

Table type support row- and colspans, but obviously parser is lacking.

Still TODO:
- Latex backend. Should we use multirow package
  https://ctan.org/pkg/multirow?lang=en?
- Hoogle backend: ?

* Implement grid-tables

* Refactor table parser

* Add two ill-examples

* Update CHANGES.md

* Basic documentation for tables

* Fix documentation example