allocate_budget_to_maximize_response() doc string could be clearer

[cluhmann]

The following arguments could use some additional clarification:

• budget_bounds: could use an example to illustrate the structure
• custom_constraints: definitely needs an example. Totally unclear how to use this at the moment.
• quantile: doc string states this is "The quantile to use for recovering transformation parameters". But a quartile of what? Why are transformation parameters being "recovered" and why are quantiles needed for this process?
• noise_level: doc string states that this is "The level of noise added to the allocation strategy". But it's not clear what this means or where this noise is added or why.

[wd60622]

@cetagostini some feedback for #1151