add quote style ```

source/Quotes.popclipext/quotes.ts

@@ -5,6 +5,7 @@ const styles = [
   '"…"',
   "'…'",
   "`…`",
+  "```…```",
   "«…»",
   "《…》",
   "‹…›",
@@ -18,6 +19,10 @@ const styles = [
 
 // generate square icon
 function makeIcon(style: string): string {
+  // Handle the case of three backticks.
+  if (style.startsWith("```")) {
+    return "[[```]]";
+  }
   return `[[${style[0]}${style[2]}]]`;
 }
 
@@ -43,7 +48,22 @@ const extension: Extension = {
             title: styles[index],
             icon: makeIcon(style),
             code: (selection) => {
-              popclip.pasteText(style[0] + selection.text + style[2]);
+              // Handle the case of three backticks.
+              if (style.startsWith("```")) {
+                // Detect the longest continuous backquote sequence in the text
+                const backtickMatch = selection.text.match(/`+/g);
+                let maxBackticks = 0;
+                if (backtickMatch) {
+                  maxBackticks = Math.max(...backtickMatch.map(m => m.length));
+                }
+                // If the text contains three or more backticks, use one more backtick than the longest sequence
+                const wrapperLength = Math.max(3, maxBackticks + 1);
+                const wrapper = "`".repeat(wrapperLength);
+                // Add line breaks before and after each line to make the backticks occupy a single line
+                popclip.pasteText(wrapper + "\n" + selection.text + "\n" + wrapper);
+              } else {
+                popclip.pasteText(style[0] + selection.text + style[2]);
+              }
             },
           };
         });