[EM] Threat/Promise Approval strategy. Summary of strategies.

[Paul Kislanko]

At the risk of showing my ignorance again,
> 
> Choice of Approval strategies depends largely on what you prefer to 
> estimate.

Somehow I think there should be a way to label posts that are about
"strategies that voters should employ for a given election method" as
opposed to "this election method can be exploited by these strategies".

The same language is used in both cases, so it can be confusing when is
concerned about the latter but finds the former irrelevant.