Set default open_mfdataset kwargs

Hardcode it in lib/__init__

docs/stylesheet.css

@@ -195,7 +195,7 @@ h1 span, h2 span, h3 span, h4 span, h5 span, h6 span {
 
 a {
     text-decoration: none;
-    color: #57d; /* TODO: Find a better colour for this. */
+    color: #57d;
 }
 
 a:hover {

lib/__init__.py

@@ -59,6 +59,7 @@ def _fixes_as_dict(fixes: List[str]):
     return {k: v for k, v in fixes}
 
 
+# Set default fixes
 if 'fixes' in DEFAULTS:
     d = DEFAULTS['fixes'].split()
     if len(d) % 2 != 0:
@@ -68,6 +69,11 @@ if 'fixes' in DEFAULTS:
     DEFAULTS_TYPES['fixes'] = dict
 
 
+# Set default open_mfdataset kwargs
+DEFAULTS['open_mf_kw'] = dict()
+DEFAULTS_TYPES['open_mf_kw'] = dict
+
+
 def check_output_dir(odir, log=None, file=False):
     """Check if directory exists, if not create it.