Merge pull request #6300 from davidhorstmann-arm/syntax-highlighting-function-files

Use GitHub C syntax highlighting on test files
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..ceb59d7
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+# Classify all '.function' files as C for syntax highlighting purposes
+*.function linguist-language=C