Replace chroma with go-highlite

testdata/custom.style

@@ -78,95 +78,7 @@
   },
   "code_block": {
     "color": "244",
-    "margin": 2,
-    "chroma": {
-      "text": {
-        "color": "#C4C4C4"
-      },
-      "error": {
-        "color": "#F1F1F1",
-        "background_color": "#F05B5B"
-      },
-      "comment": {
-        "color": "#676767"
-      },
-      "comment_preproc": {
-        "color": "#FF875F"
-      },
-      "keyword": {
-        "color": "#00AAFF"
-      },
-      "keyword_reserved": {
-        "color": "#FF5FD2"
-      },
-      "keyword_namespace": {
-        "color": "#FF5F87"
-      },
-      "keyword_type": {
-        "color": "#6E6ED8"
-      },
-      "operator": {
-        "color": "#EF8080"
-      },
-      "punctuation": {
-        "color": "#E8E8A8"
-      },
-      "name": {
-        "color": "#C4C4C4"
-      },
-      "name_builtin": {
-        "color": "#FF8EC7"
-      },
-      "name_tag": {
-        "color": "#B083EA"
-      },
-      "name_attribute": {
-        "color": "#7A7AE6"
-      },
-      "name_class": {
-        "color": "#F1F1F1",
-        "underline": true,
-        "bold": true
-      },
-      "name_constant": {},
-      "name_decorator": {
-        "color": "#FFFF87"
-      },
-      "name_exception": {},
-      "name_function": {
-        "color": "#00D787"
-      },
-      "name_other": {},
-      "literal": {},
-      "literal_number": {
-        "color": "#6EEFC0"
-      },
-      "literal_date": {},
-      "literal_string": {
-        "color": "#C69669"
-      },
-      "literal_string_escape": {
-        "color": "#AFFFD7"
-      },
-      "generic_deleted": {
-        "color": "#FD5B5B"
-      },
-      "generic_emph": {
-        "italic": true
-      },
-      "generic_inserted": {
-        "color": "#00D787"
-      },
-      "generic_strong": {
-        "bold": true
-      },
-      "generic_subheading": {
-        "color": "#777777"
-      },
-      "background": {
-        "background_color": "#373737"
-      }
-    }
+    "margin": 2
   },
   "table": {
     "center_separator": "┼",