Move newline generation in help

If we removed the shortcuts intro, we would not need the additional '\n'
of the section title, so it should be printed along with the shortcuts
intro.

app/src/cli.c

@@ -776,7 +776,7 @@ print_shortcuts_intro(unsigned cols) {
         return;
     }
 
-    printf("%s\n", intro);
+    printf("\n%s\n", intro);
     free(intro);
 }
 
@@ -831,7 +831,7 @@ scrcpy_print_usage(const char *arg0) {
     }
 
     // Print shortcuts section
-    printf("\nShortcuts:\n\n");
+    printf("\nShortcuts:\n");
     print_shortcuts_intro(cols);
     for (size_t i = 0; i < ARRAY_LEN(shortcuts); ++i) {
         print_shortcut(&shortcuts[i], cols);