chore: implement html renderer

plugin/gomark/parser/paragraph_test.go

@@ -18,6 +18,10 @@ func TestParagraphParser(t *testing.T) {
 			text:      "",
 			paragraph: nil,
 		},
+		{
+			text:      "\n",
+			paragraph: nil,
+		},
 		{
 			text: "Hello world!",
 			paragraph: &ast.Paragraph{
@@ -28,6 +32,28 @@ func TestParagraphParser(t *testing.T) {
 				},
 			},
 		},
+		{
+			text: "Hello world!\n",
+			paragraph: &ast.Paragraph{
+				Children: []ast.Node{
+					&ast.Text{
+						Content: "Hello world!",
+					},
+					&ast.LineBreak{},
+				},
+			},
+		},
+		{
+			text: "Hello world!\n\nNew paragraph.",
+			paragraph: &ast.Paragraph{
+				Children: []ast.Node{
+					&ast.Text{
+						Content: "Hello world!",
+					},
+					&ast.LineBreak{},
+				},
+			},
+		},
 	}
 
 	for _, test := range tests {