Update modifier descriptions (may require testing)

[vanderaj]

It'd be nice to have some indication of the extent to which different actions impact not just influence but also economics and security sliders. I did some testing myself and found that missions are by far the best way to boost the economy, but oddly the types of missions that boost security are not at all what you'd expect; bounty missions, for example, actually boost the ECONOMY.

Trade and Exploration, while giving significant inf effects, have very little impact on the economy slider, and interestingly rare goods trade actually has a NEGATIVE impact on economy state, probably because it has zero demand.