update translation

frontend/src/routes/document/View.svelte

@@ -218,7 +218,7 @@
         <legend>
             {t('positions')}
             {#if editable}
-            <button onclick={() => position_select = true}>{t('add_position')}</button>
+            <button onclick={() => position_select = true}>{t('add_object',{object:t('position')})}</button>
             {/if}
         </legend>
         <PositionList bind:document={doc} submit={update} bind:error={error} />