Added snippets for the pointer related operators

[pkulikov]

Supports dotnet/docs#12411

[BillWagner]

These changes all LGTM @pkulikov

I've reviewed everything, and ran the samples. I'll now, then review the related article.

[BillWagner]

@pkulikov This PR reminded me to alert you to a couple changes in practice that are coming soon. Neither affects this PR, but you should know what's coming. We'll be updating the contributor guide as part of this as well.

1. We plan to slowly retire the "snippets" folder. The distinction for snippets is arbitrary. It's based on a previous content system. We're discussing how best to map sample code to the corresponding article and provide folder guidance, but it will likely be some mapping between the article folder and the samples folder. On future PRs, let's avoid adding more code into the "snippets" folder.
2. We plan to leverage full programs over extracted bits of a method for the C# interactive experience. It's going to be some time before the full capabilities of Try.NET scaffolding is incorporated into the docs site. Until then, we're hard coding the interactive experience to use full programs. We're going to start updating the existing interactive samples soon.

[pkulikov]

@BillWagner thanks for the alert.

As for the code location, the current path to the operator snippets is

https://github.com/dotnet/samples/tree/master/snippets/csharp/language-reference/operators

Should it be the following:

https://github.com/dotnet/samples/tree/master/csharp/language-reference/operators

If that's fine, I can move existing operator snippets. Otherwise, I'll wait for the discussion outcomes on your side.

We plan to leverage full programs over extracted bits of a method for the C# interactive experience.

How would it affect the operator snippets (and other language reference snippets)?

Until then, we're hard coding the interactive experience to use full programs. We're going to start updating the existing interactive samples soon.

If something should be updated for the operator snippets in this regard, I'm fine to do that.

[BillWagner]

@pkulikov

Should it be the following:

https://github.com/dotnet/samples/tree/master/csharp/language-reference/operators

If that's fine, I can move existing operator snippets. Otherwise, I'll wait for the discussion outcomes on your side.

That's where they will go. For now, let's use that for new samples, but only move them if it's part of other work.

Until then, we're hard coding the interactive experience to use full programs. We're going to start updating the existing interactive samples soon.

If something should be updated for the operator snippets in this regard, I'm fine to do that.

You're too kind. That's a lot to ask, but thank you. I'm looking at plans to get this done as a large project on this side. If you do start on any of the migrations, please open a WIP PR when you start so I make sure not to duplicate work. Thanks again.