feat: support stylesheet tags

Author: beefchimi

languages/liquid/highlights.scm

@@ -34,6 +34,7 @@
   "endraw"
   "endschema"
   "endstyle"
+  "endstylesheet"
   "form"
   "increment"
   "javascript"
@@ -42,6 +43,7 @@
   "raw"
   "schema"
   "style"
+  "stylesheet"
   "with"
 ] @keyword
   (#set! priority 110))

languages/liquid/injections.scm

@@ -17,6 +17,11 @@
   (#set! injection.language "css")
   (#set! injection.combined))
 
+(stylesheet_statement
+  (stylesheet_content) @injection.content
+  (#set! injection.language "css")
+  (#set! injection.combined))
+
 ((front_matter) @injection.content
   (#set! injection.language "yaml"))