Overhaul code org, and improve image uploading

This commit introduces breaking changes. It overhauls how and where
services are configured and placed in the codebase, as well as moving
the entire source into src/ It also changes how these integrations
are configured via environment variables. Old configs will still work
for now, but it is strongly suggested that you migrate your config.

src/templates/views/admin/login.hbs

@@ -0,0 +1,45 @@
+<main class="flex justify-center items-center h-screen relative bg-base">
+    <div class="flex bg-surface rounded-xl overflow-hidden">
+        <img src="/assets/leaves.webp" class="h-96 w-64 object-cover" />
+        <div class="flex flex-col p-4 text-center">
+            <h2 class="text-2xl">
+                Login
+            </h2>
+            <form action="/admin/login" method="post" class="flex flex-col gap-y-3 my-2">
+                <input type="text" name="username" placeholder="Username" />
+                <input type="password" name="password" placeholder="Password" />
+                <button class="px-4 py-2 rounded-md w-full bg-accent text-white border-0" type="submit">Login</button>
+            </form>
+            <span id="message"></span>
+        </div>
+    </div>
+</main>
+
+<script>
+    let message = document.getElementById("message");
+    let form = document.querySelector("form");
+    form.addEventListener("submit", async (event) => {
+        event.preventDefault();
+        let data = {
+            "username": form.username.value,
+            "password": form.password.value
+        };
+
+        console.log(data);
+
+        let res = await fetch("/admin/login", {
+            method: "POST",
+            body: JSON.stringify(data),
+            headers: {
+                "Content-Type": "application/json"
+            }
+        });
+
+        if (res.status === 200) {
+            window.location.href = "/admin";
+            return;
+        }
+
+        message.innerText = (await res.json()).message;
+    });
+</script>