Please build me an app that lets me search "prebuilt commands" from the command line itself. I am always opening Chrome to google "how to grep recursively only

Please build me an app that lets me search "prebuilt commands" from the command line itself. I am always opening Chrome to google "how to grep recursively only files of a certain type to find phone numbers"... why can't i just search that from the command line itself and then select from the outputted suggestions? Other than that, some random ideas..: Probable command completion. Possible arguments should be displayed as I type. Syntax highlighting and beautiful margins/padding Collapsible threads