refactor: adopt template helper for 1 simple eejsBlock_* hook(s) (#11)

Replaces hand-rolled

  exports.eejsBlock_X = (hookName, args, cb) => {
    args.content += eejs.require(path[, {}, module]);
    cb();
  };

block(s) with template(path) from ep_plugin_helpers. Same runtime
behavior — eejs renders the same template into the same section.

Wave 2 of the template-adoption sweep — picks up hooks with explicit
empty-vars and/or module argument that wave 1's strict regex skipped.

Author: JohnMcLear

index.js

@@ -1,5 +1,7 @@
 'use strict';
 
+const {template} = require('ep_plugin_helpers');
+
 const store = require('./lib/padLanguageStore');
 const eejs = require('ep_etherpad-lite/node/eejs/');
 const renderer = require('./lib/exportRenderer');
@@ -96,10 +98,8 @@ exports.socketio = (hookName, {io}) => {
   });
 };
 
-exports.eejsBlock_editbarMenuLeft = (hookName, args, cb) => {
-  args.content += eejs.require('ep_hljs/templates/editbarButtons.ejs', {}, module);
-  cb();
-};
+exports.eejsBlock_editbarMenuLeft =
+    template('ep_hljs/templates/editbarButtons.ejs');
 
 exports.getLineHTMLForExport = async (hookName, context) => {
   if (!context || typeof context.lineContent !== 'string') return;

package.json

@@ -1,7 +1,7 @@
 {
   "name": "ep_hljs",
   "version": "0.1.6",
-  "description": "Whole-pad syntax highlighting for Etherpad via highlight.js. Auto-detect or pick a language; tokens are painted via the CSS Custom Highlights API — no DOM mutation, no caret drift.",
+  "description": "Whole-pad syntax highlighting for Etherpad via highlight.js. Auto-detect or pick a language; tokens are painted via the CSS Custom Highlights API \u2014 no DOM mutation, no caret drift.",
   "license": "Apache-2.0",
   "author": {
     "name": "John McLear",