DOCTYPE is missing when using emmet to create html document

Issue Type: Bug

Steps to reproduce:

Create empty html file.
Open it in vscode editor.
Type 'doc' (without quotes) and press tab.
Html document template is created, but it has no doctype.

Actual result:

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>

</body>
</html>

Expected result - notice the doctype in the beginning of template:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>

</body>
</html>

VS Code version: Code 1.25.0 (0f080e5267e829de46638128001aeb7ca2d6d50e, 2018-07-05T13:11:58.697Z) OS version: Windows_NT x64 10.0.17134

System Info

|Item|Value| |---|---| |CPUs|Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz (4 x 2592)| |GPU Status|2d_canvas: enabled
flash_3d: enabled
flash_stage3d: enabled
flash_stage3d_baseline: enabled
gpu_compositing: enabled
multiple_raster_threads: enabled_on
native_gpu_memory_buffers: disabled_software
rasterization: disabled_software
video_decode: enabled
video_encode: enabled
vpx_decode: unavailable_software
webgl: enabled
webgl2: enabled| |Memory (System)|7.91GB (0.97GB free)| |Process Argv|C:\Program Files\Microsoft VS Code\Code.exe C:\liu\projects\drawBackground\index.html| |Screen Reader|no| |VM|0%|

Extensions (7)

Extension|Author (truncated)|Version ---|---|--- vscode-eslint|dba|1.4.12 prettier-vscode|esb|1.5.0 vscode-highlight|fab|1.2.3 vs-color-picker|lih|0.7.0 emoji|Per|0.0.3 sass-indented|rob|1.4.9 vscode-import-cost|wix|2.7.2

microsoft / vscode

DOCTYPE is missing when using emmet to create html document #54680

Steps to reproduce: