Added documentation for the `except` option to the `mangle` option in the API reference.
- `parse` (default {}) — pass an object if you wish to specify some
additional [parser options][parser]. (not all options available... see below)
+##### mangle
+
+ - `except` - pass an array of identifiers that should be excluded from mangling
+
##### mangleProperties options
- `regex` — Pass a RegExp to only mangle certain names (maps to the `--mangle-regex` CLI arguments option)