bs5: form input spacing, renamed controls

src-ui/src/app/components/document-detail/document-detail.component.html

@@ -71,7 +71,7 @@
                 <li [ngbNavItem]="2">
                     <a ngbNavLink i18n>Content</a>
                     <ng-template ngbNavContent>
-                        <div class="form-group">
+                        <div class="mb-3">
                             <textarea class="form-control" id="content" rows="20" formControlName='content'></textarea>
                         </div>
                     </ng-template>