Add email templates for user notifications and account management

- Created a base email template (base.html) for consistent styling across all emails.
- Added moderation approval email template (moderation_approved.html) to notify users of approved submissions.
- Added moderation rejection email template (moderation_rejected.html) to inform users of required changes for their submissions.
- Created password reset email template (password_reset.html) for users requesting to reset their passwords.
- Developed a welcome email template (welcome.html) to greet new users and provide account details and tips for using ThrillWiki.

django/staticfiles/guardian/img/icon-no.svg

@@ -0,0 +1,3 @@
+<svg width="13" height="13" viewBox="0 0 1792 1792" xmlns="http://www.w3.org/2000/svg">
+  <path fill="#dd4646" d="M1277 1122q0-26-19-45l-181-181 181-181q19-19 19-45 0-27-19-46l-90-90q-19-19-46-19-26 0-45 19l-181 181-181-181q-19-19-45-19-27 0-46 19l-90 90q-19 19-19 46 0 26 19 45l181 181-181 181q-19 19-19 45 0 27 19 46l90 90q19 19 46 19 26 0 45-19l181-181 181 181q19 19 45 19 27 0 46-19l90-90q19-19 19-46zm387-226q0 209-103 385.5t-279.5 279.5-385.5 103-385.5-103-279.5-279.5-103-385.5 103-385.5 279.5-279.5 385.5-103 385.5 103 279.5 279.5 103 385.5z"/>
+</svg>

django/staticfiles/guardian/img/icon-yes.svg

@@ -0,0 +1,3 @@
+<svg width="13" height="13" viewBox="0 0 1792 1792" xmlns="http://www.w3.org/2000/svg">
+  <path fill="#70bf2b" d="M1412 734q0-28-18-46l-91-90q-19-19-45-19t-45 19l-408 407-226-226q-19-19-45-19t-45 19l-91 90q-18 18-18 46 0 27 18 45l362 362q19 19 45 19 27 0 46-19l543-543q18-18 18-45zm252 162q0 209-103 385.5t-279.5 279.5-385.5 103-385.5-103-279.5-279.5-103-385.5 103-385.5 279.5-279.5 385.5-103 385.5 103 279.5 279.5 103 385.5z"/>
+</svg>