[YAML] Wrong syntax highliting of lines containing # inside a multiline content

[sarod]

Issue Type: Bug

In a YAML document when a multiline value contains a line that contains a "#" vscode highlits the line as a comment instead of keeping it as a value.

For instance:
When creating a YAML document like this:

# I'm a comment
myMarkdownProperty:  |
  # I'm a markdown title
  The line above should not be cosnidered a comment

vscode highlights "# I'm a markdown title":

VS Code version: Code 1.23.1 (d0182c3, 2018-05-10T16:04:33.747Z)
OS version: Linux x64 4.13.0-41-generic

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz (8 x 2546)
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: unavailable_software video_encode: enabled vpx_decode: unavailable_software webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	15.61GB (0.54GB free)
Process Argv	/usr/share/code/code --unity-launch
Screen Reader	no
VM	0%

Extensions (16)

Extension	Author (truncated)	Version
beautify	Hoo	1.3.0
html-css-class-completion	Zig	1.17.1
path-intellisense	chr	1.4.2
typescript	cod	0.9.0
web	cod	0.9.0
vscode-eslint	dba	1.4.9
tslint	eg2	1.0.29
vscode-test-view	eti	0.2.3
auto-close-tag	for	0.5.6
code-runner	for	0.9.3
rainbow-csv	mec	0.2.1
debugger-for-chrome	msj	4.4.3
language-liquid	nei	0.0.3
typescript-hero	rbb	2.3.2
vscode-yaml	red	0.0.12
JavaScriptSnippets	xab	1.6.0

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Setting language specific tab size gets reset (#46394)
• Support JSON Schema for YAML files (#1176)

[aeschli]

duplicate of textmate/yaml.tmbundle#17