Correct key name in arduino-cli compile --dump-profile output

The `--dump-profile` flag causes Arduino CLI to print the board and sketch dependencies of that compilation as a YAML
document. This could be copied into a "sketch project file" for later use as a "build profile" specified via the
`--profile` flag.

A typo in the `profiles` key name caused the generated "build profile" entry to not be recognized when added to a
"sketch project file".

The key name is hereby corrected.

Author: per1234

Diff for: cli/compile/compile.go

@@ -303,7 +303,7 @@ func runCompileCommand(cmd *cobra.Command, args []string) {
 			newProfileName = split[2]
 		}
 		fmt.Println()
-		fmt.Println("profile:")
+		fmt.Println("profiles:")
 		fmt.Println("  " + newProfileName + ":")
 		fmt.Println("    fqbn: " + compileRequest.GetFqbn())
 		fmt.Println("    platforms:")