Incorrect docs about '*' in outputSelection

[frangio]

The documentation says that '*' will produce all available outputs:

solidity/docs/using-the-compiler.rst

Lines 406 to 407 in 2e8cd3f

	// To select all outputs the compiler can possibly generate, use
	// "outputSelection: { "*": { "*": [ "*" ], "": [ "*" ] } }"

I found this not to be the case, as confirmed by this line here:

solidity/libsolidity/interface/StandardCompiler.cpp

Lines 297 to 298 in 2e8cd3f

	/// @returns true if any Yul IR was requested. Note that as an exception, '*' does not
	/// yet match "ir", "irAst", "irOptimized" or "irOptimizedAst"