Update readme docs

[dimitryzub]

This PR focuses on:

• fix typos.

• remove duplicates, for example:

• text formatting, clarification.

• remove unnecessary examples, or possibly leave them but with details disclosure element.

• add backlinks to some terms.

• add pagination examples for all available APIs.

Pagination examples could be placed to oobt/ folder instead to test "out of the box tests" for all APIs. However, I'm not familiar with it and how things currently work so I need a little guidance before working on it 🙂

[dimitryzub]

@ilyazub would love to do that :shipit: