Improve the sample dot command call

[WallaceKelly]

In Windows PowerShell, the command dot -Tpng .\daml-project.dot > daml-project.png does not create a valid PNG file. Apparently, the > of the binary file did not work properly. Instead I used dot -T png .\daml-project.dot -o daml-project.png with -o instead of >. That is probably the preferred way.

[digitalasset-cla]

All committers have signed the CLA.

[stefanobaghino-da]

This is now stale. Next time you have an approval, please merge as soon as you can. Looks small enough that you can easily rebase and work on this, unless it's no longer relevant, in which case please close the PR.

[stefanobaghino-da]

I'll close this for now, feel free to reopen if necessary.