clean trailing whitespace in css examples

examples/code_browser.tcss

@@ -23,7 +23,7 @@ CodeBrowser.-show-tree #tree-view {
 #code-view {
     overflow: auto scroll;
     min-width: 100%;
-    hatch: right $primary;   
+    hatch: right $primary;
 }
 #code {
     width: auto;

examples/dictionary.tcss

@@ -9,7 +9,7 @@ Input {
 
 #results {
     width: 100%;
-    height: auto;    
+    height: auto;
 }
 
 #results-container {

examples/merlin.py

@@ -49,8 +49,8 @@ class LabelSwitch(Widget):
     DEFAULT_CSS = """
     LabelSwitch Label {
         text-align: center;
-        width: 1fr;       
-        text-style: bold;         
+        width: 1fr;
+        text-style: bold;
     }
 
     LabelSwitch Label#label-5 {
@@ -101,7 +101,7 @@ class MerlinApp(App):
 
     CSS = """
     Screen {
-        align: center middle;   
+        align: center middle;
     }
 
     Screen.-win {
@@ -110,8 +110,8 @@ class MerlinApp(App):
 
     Screen.-win Timer {
         color: $success;
-    }    
-    
+    }
+
     Grid {
         width: auto;
         height: auto;