feat: add unit tests

t/02-paragraphs.t

@@ -0,0 +1,25 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use Test::More tests => 3;
+use MarkdownParser;
+
+my $parser = MarkdownParser->new();
+
+is(
+    $parser->parse("Simple paragraph"),
+    "<p>Simple paragraph</p>\n",
+    "Single paragraph"
+);
+is(
+    $parser->parse("First paragraph\n\nSecond paragraph"),
+    "<p>First paragraph</p>\n<p>Second paragraph</p>\n",
+    "Multiple paragraphs"
+);
+is(
+    $parser->parse("Paragraph with\nmultiple lines"),
+    "<p>Paragraph with multiple lines</p>\n",
+    "Multi-line paragraph"
+);
+