Rewrite of the Get Started section

[ferafiks]

This is quite a large PR, so I'm going to go over everything one by one.

Why?

The get started section is probably one of the most messy sections in the documentation. There is a lot of redundancy, unnecessary detail, lack of important information and lack of structure. This PR fixes that.

Changes

There is quite a lot of them.

1. New section - Install and update

The reason why I wanted to split off the get-started into two sections, was mainly because of the update-stride page. I think, a guide on how to update the engine shouldn't be included in the section for instructing the basics. This page only becomes useful after someone has already started using Stride and by that point, they shouldn't need to consult the "get started" section.

In that regard, having a dedicated section for installing and updating makes more sense in my opinion. For reference, that's how Unity does it.

Why not remove the page?
I think that there shouldn't be a need for a page like that, but for now, Stride has it's quirks and having them documented somewhere is a good idea.

2. Moving the requirements page

I think there are too many things without a section sitting at the top of the sidebar. This section seemed like the best place for this page.

I also moved the page's location and updated it in the major release workflow page, but I can move it back if that causes any issues.

3. Trimming the installation page

The install-stride page was incredibly long and pretty much just boiled down to "press things on the screen until success". Other engines either don't have a page for that (Godot), or keep it very brief (Unity). Having such a detailed guide makes it harder to read through and harder to maintain in case the installation process changes in the future.

4. Removal of Stride Launcher page

The Stride Launcher is an incredibly straight-forward piece of software. The documentation either explained already easy to understand things or re-explained them in a worse way. The launcher is made to be intuitive to use, so I see no point in providing more information on it.

Also, it wasn't under any section for some reason which made it quite odd.

5. Removal of Visual Studio extension page

The page didn't contain much useful information. It made a lot more sense to include it in the install stride page as a section.

6. Removal of Launch Stride page

This page was a rehash of previous pages and the "launch stride" part was located at the very bottom and said to press the giant red button "Start" to start the engine. I don't think having this page is that necessary.

7. Removal of Game Studio, Assets and Scenes

The main reason is that I wanted to write different, more concise versions of these pages/sections that focused more on getting people started, than going in-depth. Also, having multiple items on the sidebar linking to the same page made it a bit weird to navigate and easier to get lost in what section you are reading.

8. Removal of "Remove Borders" section from launch a game page

Why is that there?

I also created a PR that got merged, that included a dedicated page for these sort of things.

New things

Minor:

1. Added more information in the install-stride page
2. Added a section dedicated to the installation location of Stride to the install stride page
3. Added a section dedicated to the visual studio extension to the install page

Before I start going through the major things, I want to explain what the point of the get started section is for me. Get started is supposed to be a basic guide on how to start working with the engine. It is not meant to explain everything the engine has to offer, but only what is needed. After the guide, the user is expected to either: try to create something by themselves in the engine and learn things as they go OR start reading other pages of the documentation.

In addition: I don't think the section is meant to teach a complete beginner that had no previous experience with game development on how to make games. I don't think any documentation is capable of that. It's more targeted at people who only had experience with basic frameworks, only did non-game coding or worked on games in a different engine that we don't have a dedicated guide for (which means everything except Unity).

1. Key Concepts

This page is meant to serve as a introduction to a few key terms and concepts used in Stride.

2. Game Studio

This page is meant to teach on how to use the Game Studio. It's a more shrunk down version of the game studio section, focused on explaining just the basics. This is why it skips over some of the panels.

3. Assets

This page is meant to teach about how to create assets and how they work. I skipped everything related to loading assets or using them in code, as when getting started, they will at most be used when editing a scene in Game Studio.

4. Next steps

This page is meant to direct a user to what they should do next after finishing the section.

TODO:

• - Add images to pages
• - Correct details
• - Add redirecting to moved pages if that's something that can be done

NOTE:

I don't know how long it will take me to finish this PR, because it's Christmas. This is also why I don't expect anyone to start reviewing this PR any time soon (Merry Christmas).