Restrict snippets

This commit disables snippet in ...

- comments
- literal or interpolated strings
- embedded or interpolated code blocks (from template languages)
- HTML tags
- Markdown files (but not in fenced code blocks)

Using `- source.astro <scope>` in order to only exclude scopes belonging to
possibly embedded Astro code block in question.

Snippets/component.sublime-snippet

@@ -6,6 +6,16 @@ $1
 $0
 ]]></content>
 	<tabTrigger>component</tabTrigger>
-	<scope>source.astro</scope>
+	<scope>
+		source.astro
+		- source.astro meta.tag
+		- source.astro meta.embedded
+		- source.astro meta.interpolation
+		- source.astro meta.string
+		- source.astro comment
+		- source.astro source
+		- source.astro string
+		- (text.html.markdown - markup.raw.code-fence source.astro)
+	</scope>
 	<description>Component</description>
 </snippet>

Snippets/page_html.sublime-snippet

@@ -16,6 +16,16 @@ $1
 </html>
 ]]></content>
 	<tabTrigger>page_html</tabTrigger>
-	<scope>source.astro</scope>
+	<scope>
+		source.astro
+		- source.astro meta.tag
+		- source.astro meta.embedded
+		- source.astro meta.interpolation
+		- source.astro meta.string
+		- source.astro comment
+		- source.astro source
+		- source.astro string
+		- (text.html.markdown - markup.raw.code-fence source.astro)
+	</scope>
 	<description>Page with full HTML</description>
 </snippet>

Snippets/page_layout.sublime-snippet

@@ -8,6 +8,16 @@ import ${1:Layout} from "../layouts/$1.astro"
 </$1>
 ]]></content>
 	<tabTrigger>page_layout</tabTrigger>
-	<scope>source.astro</scope>
+	<scope>
+		source.astro
+		- source.astro meta.tag
+		- source.astro meta.embedded
+		- source.astro meta.interpolation
+		- source.astro meta.string
+		- source.astro comment
+		- source.astro source
+		- source.astro string
+		- (text.html.markdown - markup.raw.code-fence source.astro)
+	</scope>
 	<description>Page from Layout</description>
 </snippet>