refactor: massive USRPFP overhaul (#3)

This repo completely overhauls how USRPFP works. Some changes include:
- Deleted some leftover files
- Edited README.md a bit
- Avatars and badges are now stored in `db/data.json`
- CSS file (`db/dist.css`) is automatically generated by a GitHub
workflow

If you have questions, lmk

db/template.css

@@ -0,0 +1,22 @@
+/* AVATAR-TEMPLATE-BEGIN */
+/* Custom avatar for {id} */
+[src^="https://cdn.discordapp.com/avatars/{id}/"]
+{
+  content: url("{img}");
+}
+/* AVATAR-TEMPLATE-END */
+
+/* BADGE-TEMPLATE-BEGIN */
+/* Custom badge for {username} */
+#app-mount [aria-label="{username}"] .badgeList-2aoHPw::before,
+#app-mount [aria-label="{username}"] .profileBadges-2pItdR::before,
+#app-mount [aria-label="{username}"] .profileBadge22-3GAYRy::before,
+#app-mount [aria-label="{username}"] .profileBadge-12r2Nm::before,
+#app-mount [aria-label="{username}"] .profileBadge24-sH1efV::before,
+#app-mount [aria-label="{username}"] .badges-XRnWAp::before {
+  content: "";
+  width: 22px;
+  height: 22px;
+  background: url("{img}") center / 100% 100%;
+}
+/* BADGE-TEMPLATE-END */