docs: fix sample code

save() returns bool.

Author: kenjis

user_guide_src/source/libraries/images/003.php

@@ -1,6 +1,5 @@
 <?php
 
-$image = \Config\Services::image()
-    ->withFile('/path/to/image/mypic.jpg')
+$image->withFile('/path/to/image/mypic.jpg')
     ->fit(100, 100, 'center')
     ->save('/path/to/image/mypic_thumb.jpg');

user_guide_src/source/libraries/images/004.php

@@ -1,7 +1,6 @@
 <?php
 
-$image = \Config\Services::image()
-    ->withFile('/path/to/image/mypic.jpg')
+$image->withFile('/path/to/image/mypic.jpg')
     ->reorient()
     ->rotate(90)
     ->crop(100, 100, 0, 0)

user_guide_src/source/libraries/images/005.php

@@ -1,6 +1,5 @@
 <?php
 
-$image = \Config\Services::image()
-    ->withFile('/path/to/image/mypic.jpg')
+$image->withFile('/path/to/image/mypic.jpg')
     // processing methods
     ->save('/path/to/image/my_low_quality_pic.jpg', 10);

user_guide_src/source/libraries/images/006.php

@@ -1,6 +1,5 @@
 <?php
 
-$image = \Config\Services::image()
-    ->withFile('/path/to/image/mypic.jpg')
+$image->withFile('/path/to/image/mypic.jpg')
     ->withResource()
     ->save('/path/to/image/my_low_quality_pic.jpg', 10);

user_guide_src/source/libraries/images/007.php

@@ -1,10 +1,11 @@
 <?php
 
+$image = \Config\Services::image();
+
 try {
-    $image = \Config\Services::image()
-        ->withFile('/path/to/image/mypic.jpg')
+    $image->withFile('/path/to/image/mypic.jpg')
         ->fit(100, 100, 'center')
         ->save('/path/to/image/mypic_thumb.jpg');
-} catch (CodeIgniter\Images\ImageException $e) {
+} catch (CodeIgniter\Images\Exceptions\ImageException $e) {
     echo $e->getMessage();
 }