fix: make callout detection case-insensitive (closes #171)

Jacky Zhao

2022-08-05 5c76d8dad9d993010c4e57c6de4e90911a3cd11a

 assets/js/clipboard.js

@@ -25,7 +25,10 @@
                () => {
                    button.blur();
                    button.innerHTML = svgCheck;
                    setTimeout(() => (button.innerHTML = svgCopy), 2000);
                    setTimeout(() => {
                     button.innerHTML = svgCopy
                     button.style.borderColor = ""
                    }, 2000);
                },
                (error) => (button.innerHTML = "Error")
            );