emphasized ST3 installation reasons & hints

[atuttle]

Since the questions continue to come in about this, there must be a way to improve the readme to hopefully at least reduce them some...

[atomi]

Create a new branch from development and call it st3 then update the package.json file. That's all that was ever needed. https://raw.githubusercontent.com/wbond/package_control/master/example-repository.json

Edit: You can set it so Sublime Text 3 only pulls from the st3 branch.

[redtopia]

I think the problem is that a lot of people who are new to ST have no idea what it means to install a package directly from github. I suggest adding some links that make it easy for people to learn, and also do a step by step manual install for those who don't have the time to learn about it.

[Demasso]

Exactly! People (who are new to ST) have no idea what the hell is github. This was also my case when I discovered ST (been using dreamweaver since 1997 until last summer) I've eventually managed to configure CF syntax and code hints in ST3 (and LOVE it!) but it's been quite a struggle. There are still quirks and I'd love to contribute to fix them but have no idea how or where to start.

[atuttle]

Note that this PR changes nothing about install instructions or the functionality of what's in the repo; it only seeks to improve on the wording regarding why ST3 requires special install instructions.