Add nwg-drawer config and theme

etc/skel/.config/nwg-drawer/drawer.css

@@ -0,0 +1,34 @@
+window {
+    background-color: #24273a;
+    color: #cad3f5
+}
+
+/* search entry */
+entry {
+    background-color: #363a4f
+}
+
+button, image {
+    background: none;
+    border: none
+}
+
+button:hover {
+    background-color: #5b6078
+}
+
+/* in case you wanted to give category buttons a different look */
+#category-button {
+    margin: 0 10px 0 10px
+}
+
+#pinned-box {
+    padding-bottom: 5px;
+    border-bottom: 1px dotted gray
+}
+
+#files-box {
+    padding: 5px;
+    border: 1px dotted gray;
+    border-radius: 15px
+}

etc/skel/.config/nwg-drawer/preferred-apps.json

@@ -0,0 +1,8 @@
+{
+  "\\.pdf$": "zathura",
+  "\\.svg$": "inkscape",
+  "\\.(jpg|png|tiff|gif)$": "swayimg",
+  "\\.(mp3|ogg|flac|wav|wma)$": "audacious",
+  "\\.(avi|mp4|mkv|mov|wav)$": "mpv",
+  "\\.(doc|docx|xls|xlsx)$": "libreoffice"
+}