Add a warning in the docs for the height param not supported yet in Provider methods

[RezaRahemtola]

In the documentation, the Provider methods (getRenderOutput , getFunctionSignatures , evaluateExpression , getFileContent ) all take an optional height param.

There are 2 problems with it:

• The doc isn't clear about the default value if not provided:

If omitted, the latest height is used (optional, default 0)
So is it the latest height or 0 ??

• Even if the param is passed, in reality it's not used in the code and hardcoded to 0, developers reading the documentation should be aware of that instead of having to look in the code.
  • https://github.com/gnolang/gno-js-client/blob/main/src/provider/websocket/ws.ts#L31
  • https://github.com/gnolang/gno-js-client/blob/main/src/provider/jsonrpc/jsonrpc.ts#L36