Add API docs for DeleteAccount and theme

- Fixes #298

docs/api.md

@@ -149,6 +149,7 @@ Only the first user will be able to be the admin.
   op: "SaveUserSettings",
   data: {
     show_nsfw: bool,
+    theme: String, // Default 'darkly'
     auth: String
   }
 }
@@ -200,6 +201,27 @@ Only the first user will be able to be the admin.
 }
 ```
 
+#### Delete Account
+
+*Permananently deletes your posts and comments*
+
+##### Request
+```rust
+{
+  op: "DeleteAccount",
+  data: {
+    auth: String
+  }
+}
+```
+##### Response
+```rust
+{
+  op: String,
+  jwt: String,
+}
+```
+
 #### Add admin
 ##### Request
 ```rust