Add demo

demo/pages/signup.wl

@@ -0,0 +1,24 @@
+include "pages/page.wl"
+include "pages/login_and_signup_style.wl"
+
+let main =
+    <main>
+        <span>Welcome!</span>
+
+        <div id="response"></div>
+
+        <form hx-post="/api/signup" hx-target="#response">
+            <input type="text"     name="username"  placeholder="username"        />
+            <input type="email"    name="email"     placeholder="email"           />
+            <input type="password" name="password1" placeholder="password"        />
+            <input type="password" name="password2" placeholder="repeat password" />
+            <input type="submit"   value="Sign-Up"  />
+            <div class="form-links">
+                <a href="">forgot password?</a>
+                |
+                <a href="">already have an account?</a>
+            </div>
+        </form>
+    </main>
+
+page("Log-In", none, style, main)