Doc editing

[OfekShilon]

Your checklist for this pull request

• [x] I've read the guidelines for contributing to this repository
• [x] I made sure to follow the project's coding style
• [x] I've updated the documentation with the relevant information (if needed)

Detailed description

It is clear a lot of work went into the GraphGridLayout documentation, but small grammatical and markdown glitches make it slightly harder than necessary to read. This is just some suggested editorial work, that would have helped me personally.

Test plan (required)

Not sure I got the meaning of

For all edges keep the node which is above above. This helps when vertical block spacing is set bigger than double edge spacing and edge shadows relationship between two blocks.

right, editing is very welcome.

[OfekShilon]

BTW the context is borrowing some graph algorithms for use in compiler-explorer: https://github.com/compiler-explorer/compiler-explorer/blob/45b743e22b37fbc8a858daddd8280eada070e807/static/graph-layout-core.ts#L29-L31

[OfekShilon]

Thank you for the spending the time making it cleaner. I sometimes get distracted in the middle of sentence, and I don't check what I have written previously. That's how you get nonsense like "read description of graph for definition for precise definition". No excuses for rest of the bad writing.

There might be one more portion off comments. There are a few important part's I didn't check yet.

Thanks for the detailed review! All your fixes are applied and marked resolved except one: please see the unresolved comment. If you still want to keep the original - no problem, I'll just restore it.