[Google Search API] `organic_results_state` documentation misses explanation and clear examples

[ilyazub]

With @kagermanov27, we noticed that Google Search API organic_results_state documentation misses explanation and clear examples. I didn't do a good job on documenting it in https://github.com/serpapi/SerpApi/pull/268.

Spell check documentation is missing explanation of the organic_results_state values.

(Ref: https://serpapi.com/spell-check)

Organic results documentation for organic_results_state is missing organic results in the screenshots, which is confusing.

(Ref: https://serpapi.com/organic-results#api-examples-organic-results-state)

Let's clarify the organic_results_state documentation by adding a few more sentences with an explanation and updating images.