Remove or Clarify "Using a Proxy" Section from the Readme

[schaferyan]

A user was confused about the Using a Proxy section. They thought it might mean they have to provide their own proxies to avoid getting blocked by Google etc.

I'm not sure if it's necessary to have this section at all - users who need to route all of their requests through their own proxy are probably capable of finding their own method of doing that.

If we do want to keep this section to help users who need to route all of their requests to SerpApi through a proxy, we should also make it clear that we handle proxies on our side and supplying their own proxy is not needed for general use.

[NateSkiles]

I'm leaning against removing the documentation for this, since requestOptions is configurable, and removing it would leave the feature undocumented.

That said, the documentation should make it clear that this is intended for edge cases, such as when users need to proxy their requests to SerpApi. It should also clarify that SerpApi continues to handle proxying requests to the search engines.

[schaferyan]

Makes sense @NateSkiles - I missed that this does in fact involve a feature specific to this package.

Yeah I think we can just clarify.