Incorrect newlines with definition list rendering

[christian-oudard]

Describe the bug

This:

### Backtesting and simulation framework
For any given strategy, we want to simulate its performance over known history. Figure out a way to take a recording of a market and estimate how well our strategy would have done if it had experienced that market.
**Who is doing this?**
: ?
**Hours spent?**
: 0

Renders differently from this:

### Backtesting and simulation framework
For any given strategy, we want to simulate its performance over known history. Figure out a way to take a recording of a market and estimate how well our strategy would have done if it had experienced that market.
**Who is doing this?**
: ?

**Hours spent?**
: 0

There's an extra newline in the second one. The first one renders incorrectly, with an extra newline before the last : 0