rename templates from .tera to .html.tera to enable auto-escaping of html

templates/session/login.html.tera

@@ -0,0 +1,21 @@
+{% extends "base" %}
+
+{% block title %}
+Login
+{% endblock title %}
+
+{% block content %}
+<h1>Login</h1>
+{% if message %}
+<p>{{ message | escape }}</p>
+{% endif %}
+<form method="post">
+    <label for="email_or_name">Username or email</label>
+    <input name="email_or_name">
+
+    <label for="password">Password</label>
+    <input type="password" name="password">
+
+    <input type="submit" value="Login"/>            
+</form>
+{% endblock content %}