fix: support old snippets so no need rush fix prod

Without this trick[^1], VM servers would need to be updated to avoid broken snippets.

Rush change prod, bad. Backwards-compatibility, better.

[^1]: https://github.com/TACC/Core-CMS-Custom/blob/8e62799/docs/port-project.md#old-custom-templates-directory

ecep_cms/src/taccsite_custom/ecep-cms/templates/page-members-css-old.html

@@ -0,0 +1 @@
+{% extends "ecep_cms/templates/snippets/page-members-css-old.html" %}

ecep_cms/src/taccsite_custom/ecep-cms/templates/page-members-css.html

@@ -0,0 +1 @@
+{% extends "ecep_cms/templates/snippets/page-members-css.html" %}

ecep_cms/src/taccsite_custom/ecep-cms/templates/page-members-js-old.html

@@ -0,0 +1 @@
+{% extends "ecep_cms/templates/snippets/page-members-js-old.html" %}

ecep_cms/src/taccsite_custom/ecep-cms/templates/page-members-js.html

@@ -0,0 +1 @@
+{% extends "ecep_cms/templates/snippets/page-members-js.html" %}

ecep_cms/src/taccsite_custom/ecep-cms/templates/site-css.html

@@ -0,0 +1 @@
+{% extends "ecep_cms/templates/snippets/site-css.html" %}

ecep_cms/src/taccsite_custom/ecep_cms/templates/snippets/site-css.html

@@ -1,4 +1,3 @@
 {% load static %}
 
-{# TODO: FP-1487: Move this to a templates/*.html that extends a site_cms one #}
 <link rel="stylesheet" href="{% static 'ecep_cms/css/site.css' %}">