Add jsonnet to language list

languages.json

@@ -623,6 +623,12 @@
       "mime": ["application/json", "application/manifest+json"],
       "extensions": ["json"]
     },
+    "Jsonnet": {
+      "line_comment": ["//", "#"],
+      "multi_line_comments": [["/*", "*/"]],
+      "quotes": [["\\\"", "\\\""], ["'", "'"]],
+      "extensions": ["jsonnet", "libsonnet"]
+    },
     "Jsx": {
       "name": "JSX",
       "line_comment": ["//"],

tests/data/jsonnet.jsonnet

@@ -0,0 +1,13 @@
+// 13 lines 7 code 4 comments 2 blanks
+
+/* /**/ */
+local func(a, b) = {
+  // very useful
+  a: a,
+  b: b,
+
+  # you forgot about me!
+  c: " /* comment in a string! */ ", 
+  e: ' // in another string ', // another after
+  f: ' # in a final string ', # comment after though
+}