add sdfdoodle template tag 🖊️ (#507)

src/simmate/website/core_components/templatetags/sdfdoodle.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+
+from django import template
+
+register = template.Library()
+
+
+@register.filter
+def sdfdoodle(obj):
+    """
+    Converts an sdf string to one that can be passed to the doodle_molecule fxn
+
+    Example use:
+    ``` html
+    {% load sdfdoodle %}
+    {{ my_object|sdfdoodle }}
+    ```
+    """
+    return obj.replace("\n", "\\n")