Enable Voice chat in Khoj Obsidian plugin

- Automatically carry out voice chats with Khoj from within Obsidian
  When send voice message, Khoj will auto respond with voice as well
- Listen to past Khoj messages as speech
- Add circular loading spinner to use while message is being converted
  to speech

src/interface/obsidian/styles.css

@@ -507,6 +507,40 @@ img.copy-icon {
     height: 16px;
 }
 
+/* Circular Loading Spinner */
+.loader {
+    width: 18px;
+    height: 18px;
+    border: 3px solid #FFF;
+    border-radius: 50%;
+    display: inline-block;
+    position: relative;
+    box-sizing: border-box;
+    animation: rotation 1s linear infinite;
+}
+.loader::after {
+    content: '';
+    box-sizing: border-box;
+    position: absolute;
+    left: 50%;
+    top: 50%;
+    transform: translate(-50%, -50%);
+    width: 18px;
+    height: 18px;
+    border-radius: 50%;
+    border: 3px solid transparent;
+    border-bottom-color: var(--flower);
+}
+
+@keyframes rotation {
+    0% {
+        transform: rotate(0deg);
+    }
+    100% {
+        transform: rotate(360deg);
+    }
+}
+
 /* Loading Spinner */
 .lds-ellipsis {
     display: inline-block;