Give table example in README.md

[davmlaw]

Thanks for the plugin!

I think it would be good to add an example markdown table to the README.md

Maybe I'm dumb, but I tried:

 | foo | bar |
 | 42 | 99 |

it didn't work, and I almost gave up and used restructured text (oh no!) but then found out this worked:

| foo | bar |
| ---- | -------:|
| 42 | 99 |

[ryanfox]

Thank you for the feedback. PRs are welcome if you want to add some examples. The table syntax is is documented here.