fix: Array.prototype.at() throws error in low version Node.js(<16.6.0) (#1976)

src/node/markdown/plugins/lineNumbers.ts

@@ -27,7 +27,8 @@ export const lineNumberPlugin = (md: MarkdownIt, enable = false) => {
 
     const lineNumbersCode = [
       ...Array(
-        lines.length - (lines.at(-1) === `<span class="line"></span>` ? 1 : 0)
+        lines.length -
+          (lines[lines.length - 1] === `<span class="line"></span>` ? 1 : 0)
       )
     ]
       .map((_, index) => `<span class="line-number">${index + 1}</span><br>`)

src/node/markdown/plugins/snippet.ts

@@ -115,7 +115,8 @@ export const snippetPlugin = (md: MarkdownIt, srcDir: string) => {
       rawTitle = ''
     ] = (rawPathRegexp.exec(rawPath) || []).slice(1)
 
-    const title = rawTitle || filename.split('/').at(-1) || ''
+    let tmpArr = filename.split('/')
+    const title = rawTitle || tmpArr[tmpArr.length - 1] || ''
 
     state.line = startLine + 1