Added additional information to select and multi select

v1.5.0 added the ability to filter the options in Select and MultiSelect prompts, however it was relatively hidden to users who did not know of the feature. This caused a slightly confusing user experience when they typed as options would just disppear. This release attempts to address this by adding an instructional message alongside the help prompt, indicating that the user can type to filter as well as use the arrow keys to navigate.