docs(scheduler):resource grouping documentation added

[xristianstefanov]

• Added Grouping in the Scheduler documentation
• New sections for Resource Grouping in all the available views

[marin-bratanov]

I recommend you rename the #code-snippet name in (/_contentTemplates/scheduler/views.md#code-snippet) to make it more meaningful. Will try to build and review in more detail over the weekend.

[marin-bratanov]

The OnInitializedAsync in the component should not have to generate resources, the service should provide them. Make sure that code is cleaned up.

Rename the headings for resource grouping in the inidividual view articles to include the view name (e.g. "Resource Grouping in the Day View") as that's the first examples people will see when landing on the Resource Grouping page.

In the Resource Grouping article, consider moving the links to the four views examples in the basics section - so people have seen one example and are familiar with the new tag and its settings before looking at rather complex code.

Add a screenshot for grouping by multiple resources. In fact, consider making headings for them, it is a nice thing to point out to people. You can have three sections - Basics, Single resource grouping (that also links to individual views examples) and Multipel Resource Grouping.

[marin-bratanov]

approving, I have not had time to check