updates highlight to ^10.0.0 (#205)

Highlight 10.0.0 contained a breaking change that impacts markdown-pdf.
This change updates the dependency in `package.json` and makes the small change to switch the order of arguments for `hljs.highlight`.

Author: bmordan

index.js

@@ -41,10 +41,10 @@ function markdownpdf (opts) {
       var self = this
 
       var mdParser = new Remarkable(opts.remarkable.preset, extend({
-        highlight: function (str, lang) {
-          if (lang && hljs.getLanguage(lang)) {
+        highlight: function (str, language) {
+          if (language && hljs.getLanguage(language)) {
             try {
-              return hljs.highlight(lang, str).value
+              return hljs.highlight(str, { language }).value
             } catch (err) {}
           }