Add fixed chat textarea option to AccessibilitySettings

Additionally, change 'send to center' to 'send to shift center'

src/lib/Setting/Pages/AccessibilitySettings.svelte

@@ -1,7 +1,6 @@
 <script lang="ts">
     import Check from "src/lib/UI/GUI/CheckInput.svelte";
     import { language } from "src/lang";
-    
     import { DBState } from 'src/ts/stores.svelte';
 
 </script>
@@ -24,6 +23,10 @@
     <Check bind:check={DBState.db.sendWithEnter} name={language.sendWithEnter}/>
 </div>
 
+<div class="flex items-center mt-2">
+    <Check bind:check={DBState.db.fixedChatTextarea} name={language.fixedChatTextarea}/>
+</div>
+
 <div class="flex items-center mt-2">
     <Check bind:check={DBState.db.clickToEdit} name={language.clickToEdit}/>
 </div>