Update effect.txt

Many description fixes.
1. Selfdestruct and Explosion halve the target's Defense.
2. Tri Attack, Waterfall and Dizzy Punch haven't any effects.
3. Pay Day scatters money on the ground worth two times the user's level. (Don't know if it is important for PO, but still I fixed it)
4. Whirlwind and Roar fail in a Trainer-Battle.
5. The user loses only 1 HP if Hi Jump Kick or Jump Kick misses.
6. SolarBeam does not have to charge during Sunny Day.
7. When you use rage, you cannot do anythng until the user faints.
8. When you use Rest, you only sleep one round.
9. Struggle has 1/2 recoil.
10. Minor spelling fixes.