Improve grammar in docs/Basics

[medavox]

This is just a few small corrections to some minor second-language grammar mistakes; also improving readability and punctuation in a few places.

I've also replaced the phrase 'get full code here' with 'get the full code here', because that sounds more natural to me. But Englishes do differ, and is a very minor thing anyway. I understand this is a pretty ubiquitous phrase, and I've only changed it in this one document, so I've kept those changes in a separate commit so you can reject them (and keep the others) if you don't think that's a worthwhile change.

[elizarov]

Thanks a lot. Indeed, that the full code reads better. Can you then, please, search & replace for it in all *.md files in docs folder for consistency and add to this PR, too.

[medavox]

OK, will do.

[medavox]

Done. I'm still reading the guide and learning how to use coroutines, so there may be further proofreading commits to come, but there may not. No promises.

[elizarov]

Thanks. I've merged it into master with a couple of corrections (consistent the runBlocking and added docs link to the coroutineScope function mention).

[medavox]

thanks!