fix(docs): correct typos in contributing guidelines (#13233)

Author: timberrrrrr

cli/disputer.go

@@ -95,7 +95,7 @@ var disputerMsgCmd = &cli.Command{
 		})
 
 		if aerr != nil {
-			return xerrors.Errorf("failed to serailize params: %w", aerr)
+			return xerrors.Errorf("failed to serialize params: %w", aerr)
 		}
 
 		dmsg := &types.Message{
@@ -380,7 +380,7 @@ func makeDisputeWindowedPosts(ctx context.Context, api v0api.FullNode, dl minerD
 		})
 
 		if aerr != nil {
-			return nil, xerrors.Errorf("failed to serailize params: %w", aerr)
+			return nil, xerrors.Errorf("failed to serialize params: %w", aerr)
 		}
 
 		dispute := &types.Message{

storage/sealer/ffiwrapper/sealer.go

@@ -20,7 +20,7 @@ type ExternalSealer struct {
 type Sealer struct {
 	sectors SectorProvider
 
-	// externCalls cointain overrides for calling alternative sealing logic
+	// externCalls contain overrides for calling alternative sealing logic
 	externCalls ExternalSealer
 
 	stopping chan struct{}