Updating sgf-parsing exercise instructions

Exercism Building Exercism
1

The second line in the sgf-parsing exercise docs says:

[SGF](https://en.wikipedia.org/wiki/Smart_Game_Format) is a standard format for storing board game files, in particular go.

Main issue is that the ‘go’ should be written as ‘Go’. Also, it’s not clear it refers to the game of Go unless someone clicks the link. I propose the following change:

[SGF](https://en.wikipedia.org/wiki/Smart_Game_Format) is a standard format for storing board game files, particularly for the game of Go.

or

[SGF](https://en.wikipedia.org/wiki/Smart_Game_Format) is a standard format for storing board game files, particularly for Go.

Other issues include:

  1. Missing punctuation in few places.
  2. Not one sentence per line in multiple places.
2

A link for Go could be helpful, too. I think a PR would be good.

3

Adding a link to Go crossed my mind, but then i realized that the linked article talks mostly about Go and has plenty of links to its Wikipedia page. Maybe an extra link from the instructions.md is a bit redundant? Or, is it still good practice?

4

Also, lines 57-59 say:

All property values will be the [SGF Text type][sgf-text]. You don't need to implement any other value type. Although you can read the [full documentation of the Text type][sgf-text], a summary of the important points is below:

Note that this has both ‘SGF Text type’ and ‘full documentation of the Text type’ pointing to the exact same link ‘sgf-text’. I think the second link can be safely removed.

5

I’ve noticed that the backticks were not used consistently, so i’ve fixed those as well.

Here are the current commits