Change "resize to fit" shortcut to MOD+w

For convenience, MOD+x will be used for injecting the CUT keycode.

README.md

@@ -594,7 +594,7 @@ _[Super] is typically the "Windows" or "Cmd" key._
  | Rotate display left                         | `MOD`+`←` _(left)_
  | Rotate display right                        | `MOD`+`→` _(right)_
  | Resize window to 1:1 (pixel-perfect)        | `MOD`+`g`
- | Resize window to remove black borders       | `MOD`+`x` \| _Double-click¹_
+ | Resize window to remove black borders       | `MOD`+`w` \| _Double-click¹_
  | Click on `HOME`                             | `MOD`+`h` \| _Middle-click_
  | Click on `BACK`                             | `MOD`+`b` \| _Right-click²_
  | Click on `APP_SWITCH`                       | `MOD`+`s`

app/scrcpy.1

@@ -237,7 +237,7 @@ Rotate display right
 Resize window to 1:1 (pixel\-perfect)
 
 .TP
-.B MOD+x, Double\-click on black borders
+.B MOD+w, Double\-click on black borders
 Resize window to remove black borders
 
 .TP

app/src/cli.c

@@ -214,7 +214,7 @@ scrcpy_print_usage(const char *arg0) {
         "    MOD+g\n"
         "        Resize window to 1:1 (pixel-perfect)\n"
         "\n"
-        "    MOD+x\n"
+        "    MOD+w\n"
         "    Double-click on black borders\n"
         "        Resize window to remove black borders\n"
         "\n"

app/src/input_manager.c

@@ -398,7 +398,7 @@ input_manager_process_key(struct input_manager *im,
                     screen_switch_fullscreen(im->screen);
                 }
                 return;
-            case SDLK_x:
+            case SDLK_w:
                 if (!shift && !repeat && down) {
                     screen_resize_to_fit(im->screen);
                 }