README: update for concept exercises

[pwadsworth]

Adds concepts and concept exercises entries.

Corrects folder structure to include concepts.

[pwadsworth]

Finally starting to get the hang of putting PRs.in order. Thanks for the patience!

[petertseng]

Of course. One of the things I find in open source is that patience and understanding is needed from both sides, because most of it is volunteer work. Just as I have to guide all contributors to do their best work, I have to also be thankful that they're willing to put in the time at all and put up with the changes I ask for, even if I may seem ungrateful.

[pwadsworth]

Corrected link and alignment. Tripled checked and found no other problems 🤞

[petertseng]

Great, thanks

[pwadsworth]

@petertseng: The commits you made left my fork 5 commits ahead of exercism/haskell (plus 1 when I merged), but there are no changes in the files. What is the correct way forward? do I make another pull request with the 6 commits and no file changes or reset (read delete and fork again) my fork?

[pwadsworth]

I am going to go with option 2. There are other differences with my local repos and I lost track of which one is which.

[petertseng]

You could reset, but the reset I had in mind doesn't involve deleting and forking again; resetting involves using git reset, potentially git reset --hard. When a word already means something in a particular context ("reset" has a specific meaning in the context of Git), using it to mean something other than its usual meaning should be avoided.