feat: content import system - Markdown parser, importer, 7 decks + 3 tutorials + 5 cheatsheets

edu/js/markdown.js

@@ -0,0 +1,56 @@
+'use strict';
+
+var Markdown = {
+    render: function(md) {
+        if (!md) return '';
+        var html = md;
+
+        // Code blocks
+        html = html.replace(/```(\w*)\n([\s\S]*?)```/g, function(_, lang, code) {
+            return '<pre><code class="lang-' + lang + '">' + Markdown.esc(code.trim()) + '</code></pre>';
+        });
+
+        // Inline code
+        html = html.replace(/`([^`]+)`/g, '<code>$1</code>');
+
+        // Bold
+        html = html.replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>');
+
+        // Italic
+        html = html.replace(/\*(.+?)\*/g, '<em>$1</em>');
+
+        // Headings
+        html = html.replace(/^### (.+)$/gm, '<h3>$1</h3>');
+        html = html.replace(/^## (.+)$/gm, '<h2>$1</h2>');
+        html = html.replace(/^# (.+)$/gm, '<h1>$1</h1>');
+
+        // HR
+        html = html.replace(/^---$/gm, '<hr>');
+
+        // Tables
+        html = html.replace(/^\|(.+)\|\s*\n\|[-| :]+\|\s*\n((?:\|.+\|\s*\n?)*)/gm, function(_, header, rows) {
+            var ths = header.split('|').map(function(h) { return '<th>' + h.trim() + '</th>'; }).join('');
+            var trs = rows.trim().split('\n').map(function(row) {
+                var tds = row.replace(/^\||\|$/g, '').split('|').map(function(c) { return '<td>' + c.trim() + '</td>'; }).join('');
+                return '<tr>' + tds + '</tr>';
+            }).join('');
+            return '<table><thead><tr>' + ths + '</tr></thead><tbody>' + trs + '</tbody></table>';
+        });
+
+        // Lists
+        html = html.replace(/^- (.+)$/gm, '<li>$1</li>');
+        html = html.replace(/(<li>[\s\S]*?<\/li>)/g, function(match) {
+            if (match.indexOf('<ul>') === -1) return '<ul>' + match + '</ul>';
+            return match;
+        });
+
+        // Paragraphs
+        html = html.replace(/^(?!<[huptlo]|<\/|<hr|<pre|<li|<ul)(.+)$/gm, '<p>$1</p>');
+
+        return html;
+    },
+
+    esc: function(str) {
+        return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
+    }
+};