[Docs] Show how to download from GitHub in more places

[DNin01]

The first target for anyone with no experience with GitHub, contributing, or browser extensions would probably be the Installing page from the docs, which tells you how to install ScratchTools from web stores, but web store installations aren't meant to be for modifying code, in fact, I think the browser might even throw an error if you do. The next obvious place to go to is Building a Feature, but it says nothing about running ScratchTools or how to test the modified code, and these users will want to test their changes.

There are a few ways we could solve this:

• Installing Beta does go through the developer-oriented way to install the extension that you would use to test the changes you made. We could link to it from Building a Feature to make sure the user understands how to test their changes.

• We could also add a note to Installing that tells you what to do if you plan to make changes or contribute, again, linking to Installing Beta, like the How do I download ScratchTools? FAQ sort of does.

• We could also link to those instructions from the CONTRIBUTING.md file in this repository.

While we're at it, we should also note that you should be testing your changes before you submit them.

[rgantzos]

I like this. We recently changed our documentation website and information (STForScratch/docs) and we definitely need to incorporate it into GitHub and our website better. Part of that means updating the documentation to better support new contributors/people looking to contribute.

[MaterArc]

Yeah, I agree. Many people ask about how to download the beta. This would help to inform and direct users to the right place more easily. Great idea!

[DNin01]

I'll see what I can do.