First pass at documentations.

projectile.go

@@ -6,6 +6,7 @@ import (
 	v "bitbucket.org/hackerbots/vector"
 )
 
+// Projectile are the things robots can shoot at eachother.
 type Projectile struct {
 	Id       string    `json:"id"`
 	Position v.Point2d `json:"position"`
@@ -17,6 +18,9 @@ type Projectile struct {
 	Delta    float32
 }
 
+// Projectile.Tick is called every game tick and moves projectiles along,
+// determines when they should blow up, and how damaage is propagated to
+// players.
 func (p *Projectile) Tick(g *Game) {
 	vec := p.MoveTo.Sub(p.Position)
 	v_norm := vec.Normalize()