Syntax: add clang-format (#2076)

Highlight .clang-format files as YAML

Co-authored-by: Ari Archer <truncateddinosour@gmail.com>
Co-authored-by: David Peter <mail@david-peter.de>

src/syntax_mapping.rs

@@ -41,6 +41,9 @@ impl<'a> SyntaxMapping<'a> {
     pub fn builtin() -> SyntaxMapping<'a> {
         let mut mapping = Self::empty();
         mapping.insert("*.h", MappingTarget::MapTo("C++")).unwrap();
+        mapping
+            .insert(".clang-format", MappingTarget::MapTo("YAML"))
+            .unwrap();
         mapping.insert("*.fs", MappingTarget::MapTo("F#")).unwrap();
         mapping
             .insert("build", MappingTarget::MapToUnknown)