added cactus theme files

hugo-content/themes/cactus/static/js/code-copy.js

@@ -0,0 +1,36 @@
+(() => {
+
+  function createCopyButton(codeNode) {
+    const copyBtn = document.createElement('button')
+    copyBtn.className = 'code-copy-btn'
+    copyBtn.type = 'button'
+    copyBtn.innerText = 'copy'
+
+    let resetTimer
+    copyBtn.addEventListener('click', () => {
+      navigator.clipboard.writeText(codeNode.innerText).then(() => {
+        copyBtn.innerText = 'copied!'
+      }).then(() => {
+        clearTimeout(resetTimer)
+        resetTimer = setTimeout(() => {
+          copyBtn.innerText = 'copy'
+        }, 1000)
+      })
+    })
+
+    return copyBtn
+  }
+
+  document.querySelectorAll('pre > code')
+  .forEach((codeNode) => {
+    const copyBtn = createCopyButton(codeNode);
+    const preNode = codeNode.parentNode
+    codeNode.parentNode.insertBefore(copyBtn, codeNode)
+  })
+
+  document.querySelectorAll('.highlight table > tbody > tr > td:first-child .code-copy-btn')
+  .forEach((btn) => {
+    btn.remove()
+  })
+
+})()