Properly handle linebreaks in tables

[jakewvincent]

Properly format tables with rows ending in a backslash. E.g. the following

| Name | Default | Possible values            |
| ---- | ------- | -------------------------- |
| blah | true    | This is the first option \
This is the second option  |
| bleh | false   | Generic options            |
| blih | true    | Generic options            |
| bloh | false   | Generic options            |
| bluh | true    | Generic options            |

should be formatted as such:

| Name | Default | Possible values            |
| ---- | ------- | -------------------------- |
| blah | true    | This is the first option \
                   This is the second option  |
| bleh | false   | Generic options            |
| blih | true    | Generic options            |
| bloh | false   | Generic options            |
| bluh | true    | Generic options            |

Needs:

• Make user-configurable (this breaks table rendering for certain renderers, e.g. GitHub, but it is supported by Pandoc).