feature: allow user to control whether or not to enable syntax highlighting in DiffView.

src/SourceGit/Resources/Icons.axaml

@@ -85,4 +85,5 @@
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+  <StreamGeometry x:Key="Icons.SyntaxHighlight">M875 128h-725A107 107 0 0043 235v555A107 107 0 00149 896h725a107 107 0 00107-107v-555A107 107 0 00875 128zm-115 640h-183v-58l25-3c15 0 19-8 14-24l-22-61H419l-28 82 39 2V768h-166v-58l18-3c18-2 22-11 26-24l125-363-40-4V256h168l160 448 39 3zM506 340l-72 218h145l-71-218h-2z</StreamGeometry>
 </ResourceDictionary>

src/SourceGit/Resources/Locales.Designer.cs

@@ -1284,6 +1284,15 @@ namespace SourceGit.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Syntax Highlighting.
+        /// </summary>
+        public static string Text_Diff_SyntaxHighlight {
+            get {
+                return ResourceManager.GetString("Text.Diff.SyntaxHighlight", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Open With Merge Tool.
         /// </summary>

src/SourceGit/Resources/Locales.en.resx

@@ -1287,4 +1287,7 @@
   <data name="Text.Cut" xml:space="preserve">
     <value>Cut</value>
   </data>
+  <data name="Text.Diff.SyntaxHighlight" xml:space="preserve">
+    <value>Syntax Highlighting</value>
+  </data>
 </root>

src/SourceGit/Resources/Locales.resx

@@ -1287,4 +1287,7 @@
   <data name="Text.Cut" xml:space="preserve">
     <value>Cut</value>
   </data>
+  <data name="Text.Diff.SyntaxHighlight" xml:space="preserve">
+    <value>Syntax Highlighting</value>
+  </data>
 </root>

src/SourceGit/Resources/Locales.zh.resx

@@ -1287,4 +1287,7 @@
   <data name="Text.Cut" xml:space="preserve">
     <value>剪切</value>
   </data>
+  <data name="Text.Diff.SyntaxHighlight" xml:space="preserve">
+    <value>语法高亮</value>
+  </data>
 </root>