all: fix typos (#2859)

CONTRIBUTING.md

@@ -22,7 +22,7 @@ You can ask us at these communities:
 
 ## Following the Go convention
 
-Please follow the Go convension like [Effective Go](https://golang.org/doc/effective_go.html).
+Please follow the Go convention like [Effective Go](https://golang.org/doc/effective_go.html).
 For example, formatting by `go fmt` is required.
 
 ## Adding copyright comments to each file

examples/audio/main.go

@@ -344,7 +344,7 @@ func (p *Player) draw(screen *ebiten.Image) {
 	cy := float32(y) + float32(h)/2
 	vector.DrawFilledCircle(screen, cx, cy, 12, playerCurrentColor, true)
 
-	// Compose the curren time text.
+	// Compose the current time text.
 	m := (c / time.Minute) % 100
 	s := (c / time.Second) % 60
 	currentTimeStr := fmt.Sprintf("%02d:%02d", m, s)

examples/audiopanning/main.go

@@ -85,7 +85,7 @@ func (g *Game) initAudioIfNeeded() {
 	g.player.Play()
 }
 
-// time is whithin the 0 ... 1 range
+// time is within the 0 ... 1 range
 func lerp(a, b, t float64) float64 {
 	return a*(1-t) + b*t
 }